Methods of using gpr 119 receptor to identify compounds useful for increasing bone mass in an individual

ABSTRACT

The present invention relates to methods of using GPR119 receptor to identify compounds useful for increasing bone mass in an individual. Agonists of GPR119 receptor are useful as therapeutic agents for treating or preventing a condition characterized by low bone mass, such as osteoporosis, and for increasing bone mass in an individual. Agonists of GPR119 receptor promote bone formation in an individual.

FIELD OF THE INVENTION

The present invention relates to methods of using GPR119 receptor toidentify compounds useful for increasing bone mass in an individual.Agonists of GPR119 receptor are useful as therapeutic agents fortreating or preventing a condition characterized by low bone mass, suchas osteoporosis, and for increasing bone mass in an individual. Agonistsof GPR119 receptor promote bone formation in an individual.

BACKGROUND OF THE INVENTION

The following discussion is intended to facilitate the understanding ofthe invention, but is not intended nor admitted to be prior art to theinvention.

A. Osteoporosis

Osteoporosis is a disabling disease characterized by the loss of bonemass and microarchitectural deterioration of skeletal structure leadingto compromised bone strength, which predisposes a patient to increasedrisk of fragility fractures. Osteoporosis affects more than 75 millionpeople in Europe, Japan and the United States, and causes more than 2.3million fractures in Europe and the United States alone. In the UnitedStates, osteoporosis affects at least 25% of all post-menopausal whitewomen, and the proportion rises to 70% in women older than 80 years. Onein three women older than 50 years will have an osteoporotic fracturethat causes a considerable social and financial burden on society. Thedisease is not limited to women; older men also can be affected. By2050, the worldwide incidence of hip fracture in men is projected toincrease by 310% and 240% in women. The combined lifetime risk for hip,forearm, and vertebral fractures presenting clinically is around 40%,equivalent to the risk for cardiovascular disease. Osteoporoticfractures therefore cause substantial mortality, morbidity, and economiccost. With an ageing population, the number of osteoporotic fracturesand their costs will at least double in the next 50 years unlesseffective preventive strategies are developed. (See, e.g., Atik et al.,Clin Orthop Relat Res (2006) 443:19-24; Raisz, J Clin Invest (2005)115:3318-3325; and World Health Organization Technical Report Series 921(2003), Prevention and Management of Osteoporosis.)

B. Glucose-dependent Insulinotropic Polypeptide (GIP)

Glucose-dependent insulinotropic polypeptide (GIP, also known as gastricinhibitory polypeptide) is a peptide incretin hormone of 42 amino acidsthat is released from duodenal endocrine K cells after meal ingestion.The amount of GIP released is largely dependent on the amount of glucoseconsumed. GIP has been shown to stimulate glucose-dependent insulinsecretion in pancreatic beta cells. GIP mediates its actions through aspecific G protein-coupled receptor, namely GIPR.

As GIP contains an alanine at position 2, it is an excellent substratefor dipeptidyl peptidase-4 (DPP-IV), an enzyme regulating thedegradation of GIP. Full-length GIP(1-42) is rapidly converted tobioinactive GIP(3-42) within minutes of secretion from the gut K cell.Inhibition of DPP-IV has been shown to augment GIP bioactivity. (See,e.g., Drucker, Cell Metab (2006) 3:153-165; McIntosh et al., Regul Pept(2005) 128:159-165; Deacon, Regul Pept (2005) 128:117-124; and Ahren etal., Endocrinology (2005) 146:2055-2059.) Analysis of full lengthbioactive GIP, for example in blood, can be carried out usingN-terminal-specific assays (see, e.g., Deacon et al, J Clin EndocrinolMetab (2000) 85:3575-3581).

Recently, GIP has been shown to promote bone formation. GIP has beenshown to activate osteoblastic receptors, resulting in increases incollagen type I synthesis and alkaline phosphatase activity, bothassociated with bone formation. GIP has been shown to inhibit osteoclastactivity and differentiation in vitro. GIP administration has been shownto prevent the bone loss due to ovariectomy. GIP receptor (GIPR)knockout mice evidence a decreased bone size, lower bone mass, alteredbone microarchitecture and biochemical properties, and alteredparameters for bone turnover, especially in bone formation. (See, e.g.,Zhong et al, Am J Physiol Endocrinol Metab (2007) 292:E543-E548; Bollaget al., Endocrinology (2000) 141:1228-1235; Bollag et al., Mol CellEndocrinol (2001) 177:35-41; Xie et al., Bone (2005) 37:759-769; andTsukiyama et al., Mol Endocrinol (2006) 20:1644-1651.)

The usefulness of GIP for maintaining or increasing bone density orformation has been acknowledged by the United State Trademark and PatentOffice by issuance of U.S. Pat. No. 6,410,508 for the treatment ofreduced bone mineralization by administration of GIP peptide. However,current GIP peptide agonists suffer from a lack of oral bioavailability,negatively impacting patient compliance. An attractive alternativeapproach is to develop an orally active composition for increasing anendogenous level of GIP activity.

C. GPR119

GPR119 is a G protein-coupled receptor (GPR119; e.g., human GPR119,GenBank® Accession No. AAP72125 and alleles thereof; e.g., mouse GPR119,GenBank® Accession No. AY288423 and alleles thereof). GPR119 activationas by an agonist leads to elevation of the level of intracellular cAMP,consistent with GPR119 being coupled to Gs. In the patent literature,GPR119 has been referred to as RUP3 (e.g., WO 00/31258); GPR119 has alsobeen referred to as Glucose-Dependent Insulinotropic Receptor (GDIR).

D. G Protein-Coupled Receptors

Although a number of receptor classes exist in humans, by far the mostabundant and therapeutically relevant is represented by the Gprotein-coupled receptor (GPCR) class. It is estimated that there aresome 30,000-40,000 genes within the human genome, and of these,approximately 2% are estimated to code for GPCRs.

GPCRs represent an important area for the development of pharmaceuticalproducts. Drugs active at GPCRs have therapeutic benefit across a broadspectrum of human diseases as diverse as pain, cognitive dysfunction,hypertension, peptic ulcers, rhinitis, and asthma. Of the approximately500 clinically marketed drugs, greater than 30% are modulators of GPCRfunction. These drugs exert their activity at approximately 30well-characterized GPCRs. (See, e.g., Wise et al, Annu Rev PharmacolToxicol (2004) 44:43-66.)

GPCRs share a common structural motif, having seven sequences of between22 to 24 hydrophobic amino acids that form seven alpha helices, each ofwhich spans the membrane (each span is identified by number, i.e.,transmembrane-1 (TM-1), transmembrane-2 (TM-2), etc.). The transmembranehelices are joined by strands of amino acids between transmembrane-2 andtransmembrane-3, transmembrane-4 and transmembrane-5, andtransmembrane-6 and transmembrane-7 on the exterior, or “extracellular”side, of the cell membrane (these are referred to as “extracellular”regions 1, 2 and 3 (EC-1, EC-2 and EC-3), respectively). Thetransmembrane helices are also joined by strands of amino acids betweentransmembrane-1 and transmembrane-2, transmembrane-3 andtransmembrane-4, and transmembrane-5 and transmembrane-6 on theinterior, or “intracellular” side, of the cell membrane (these arereferred to as “intracellular” regions 1, 2 and 3 (IC-1, IC-2 and IC-3),respectively). The “carboxy” (“C”) terminus of the receptor lies in theintracellular space within the cell, and the “amino” (“N”) terminus ofthe receptor lies in the extracellular space outside of the cell.

Generally, when a ligand binds with the receptor (often referred to as“activation” of the receptor), there is a change in the conformation ofthe receptor that facilitates coupling between the intracellular regionand an intracellular “G-protein.” It has been reported that GPCRs are“promiscuous” with respect to G proteins, i.e., that a GPCR can interactwith more than one G protein. See, Kenakin, Life Sciences (1988)43:1095-1101. Although other G proteins exist, currently, Gq, Gs, Gi, Gzand Go are G proteins that have been identified. Ligand-activated GPCRcoupling with the G-protein initiates a signaling cascade process(referred to as “signal transduction”). Under normal conditions, signaltransduction ultimately results in cellular activation or cellularinhibition. Although not wishing to be bound to theory, it is thoughtthat the IC-3 loop as well as the carboxy terminus of the receptorinteract with the G protein.

There are also promiscuous G proteins, which appear to couple severalclasses of GPCRs to the phospholipase C pathway, such as G15 or G16(Offermanns & Simon, J Biol Chem (1995) 270:15175-80), or chimeric Gproteins designed to couple a large number of different GPCRs to thesame pathway, e.g. phospholipase C (Milligan & Rees, Trends inPharmaceutical Sciences (1999) 20:118-24).

Under physiological conditions, GPCRs exist in the cell membrane inequilibrium between two different conformations: an “inactive” state andan “active” state. A receptor in an inactive state is unable to link tothe intracellular signaling transduction pathway to initiate signaltransduction leading to a biological response. Changing the receptorconformation to the active state allows linkage to the transductionpathway (via the G-protein) and produces a biological response.

A receptor may be stabilized in an active state by a ligand or acompound such as a drug. Recent discoveries, including but notexclusively limited to modifications to the amino acid sequence of thereceptor, provide means other than ligands or drugs to promote andstabilize the receptor in the active state conformation. These meanseffectively stabilize the receptor in an active state by simulating theeffect of a ligand binding to the receptor. Stabilization by suchligand-independent means is termed “constitutive receptor activation.”

SUMMARY OF THE INVENTION

The present invention relates to the unexpected discovery by Applicantthat administration of a GPR119 agonist to an individival, such as byoral administration, can act at GPR119 receptor to increase a GIP levelin the individual. The present invention features methods relating toGPR119 for identifying GIP secretagogues, compounds useful for treatingor preventing a condition characterized by low bone mass, such asosteoporosis, and compounds useful for increasing bone mass in anindividual. A GPR119 agonist is useful for promoting (e.g., increasing)bone formation in an individual. In certain embodiments, the individualis a human.

Nucleotide sequence encoding human GPR119 polypeptide is given in SEQ IDNO: 1. The amino acid sequence of said encoded human GPR119 polypeptideis given in SEQ ID NO: 2.

In a first aspect, the invention features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) contacting a test compound with a host cell or with membrane        of a host cell comprising a G protein-coupled receptor, wherein        the G protein-coupled receptor comprises an amino acid sequence        selected from the group consisting of:        -   (i) amino acids 1-335 of SEQ ID NO:2;        -   (ii) amino acids 2-335 of SEQ ID NO:2;        -   (iii) amino acids 2-335 of SEQ ID NO:2, with the proviso            that the G protein-coupled receptor does not comprise the            amino acid sequence of SEQ ID NO:2;        -   (iv) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide that is amplifiable by            polymerase chain reaction (PCR) on a human DNA sample using            specific primers SEQ ID NO:3 and SEQ ID NO:4;        -   (v) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide hybridizing under conditions of            high stringency to the complement of SEQ ID NO:1;        -   (vi) a variant of SEQ ID NO: 2;        -   (vii) the amino acid sequence of (vi) when selected from the            group consisting of:            -   (a′) the amino acid sequence of a G protein-coupled                receptor having at least about 80% identity to SEQ ID                NO: 2; and            -   (b′) an amino acid sequence of a 0 protein-coupled                receptor comprising at least 20 contiguous amino acids                of SEQ ID NO: 2;        -   (viii) the amino acid sequence of a constitutively active            version of a G protein-coupled receptor having SEQ ID NO: 2;            and        -   (ix) a biologically active fragment of any one of (i) to            (viii); and    -   (b) determining the ability of the test compound to stimulate        functionality of the G protein-coupled receptor;        wherein the ability of the test compound to stimulate        functionality of the G protein-coupled receptor is indicative of        the test compound being a GIP secretagogue, a compound useful        for treating or preventing a condition characterized by low bone        mass, or a compound useful for increasing bone mass in an        individual.

In certain embodiments, the G protein-coupled receptor comprises theamino acid sequence of a G protein-coupled receptor having at leastabout 80% identity to SEQ ID NO: 2.

In certain embodiments, the G protein-coupled receptor comprises theamino acid sequence of SEQ ID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an allele of SEQID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an ortholog ofSEQ ID NO: 2. In certain embodiments, the variant of SEQ ID NO: 2 is amammalian ortholog of SEQ ID NO: 2.

In certain embodiments, the G protein-coupled receptor is recombinant.

In certain embodiments, the method is a method for identifying GIPsecretagogues.

In certain embodiments, the method comprises identifying an agonist ofthe receptor.

In certain embodiments, the method comprises identifying a partialagonist of the receptor.

In certain embodiments, the method is a method for identifying compoundsuseful for treating or preventing a condition characterized by low bonemass

In certain embodiments, the method is a method for identifying compoundsuseful for increasing bone mass in an individual.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising steps (a) and (b) of this firstaspect, and further comprising:

-   -   (c) optionally synthesizing a compound which stimulates the        functionality of the receptor in step (b);    -   (d) contacting a compound which stimulates functionality of the        receptor in step (b) in vitro with a vertebrate enteroendocrine        cell or with a cell capable of secreting GIP; and    -   (e) determining whether the compound stimulates GIP secretion        from the vertebrate enteroendocrine cell or from the cell        capable of secreting GIP;        wherein the ability of the test compound to stimulate GIP        secretion from the vertebrate enteroendocrine cell or from the        cell capable of secreting GIP is indicative of the test compound        being a GIP secretagogue, a compound useful for treating or        preventing a condition characterized by low bone mass, or a        compound useful for increasing bone mass in an individual.

In certain embodiments, the vertebrate enteroendocrine cell is amammalian enteroendocrine cell. In certain embodiments, theenteroendocrine cell is a K cell. In certain embodiments, theenteroendocrine cell comprises tissue derived from the small intestine.In certain embodiments, the enteroendocrine cell comprises tissuederived from a K cell rich region of small intestine. In certainembodiments, the enteroendocrine cell comprises duodenum or jejunumtissue (see, e.g., Sondhi et al, Pharmacogenomics J (2006) 6:131-140).In certain embodiments, the enteroendocrine cell is an enteroendocrinecell line. In certain embodiments, the cell capable of secreting GIP isa recombinant cell engineered to be capable of secreting GIP.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising steps (a) and (b) of this firstaspect, and further comprising:

-   -   (c) optionally synthesizing a compound which stimulates        functionality of the receptor in step (b);    -   (d) administering a compound which stimulates functionality of        the receptor in step (b) to a vertebrate; and    -   (e) determining whether the compound increases a GIP level in        the vertebrate;        wherein the ability of the test compound to increase a GIP level        in the vertebrate is indicative of the test compound being a GIP        secretagogue, a compound useful for treating or preventing a        condition characterized by low bone mass, or a compound useful        for increasing bone mass in an individual.

In certain embodiments, the GIP level is blood or plasma concentrationof total GIP. In certain embodiments, the GIP level is blood or plasmaconcentration of bioactive GIP.

In certain embodiments, the vertebrate is a mammal. In certainembodiments, the vertebrate is a non-human vertebrate. In certainembodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal.

The invention additionally features a method for identifying compoundsuseful for preventing or treating a condition characterized by low bonemass or compounds useful for increasing bone mass in an individual,comprising steps (a) and (b) of this first aspect, and furthercomprising:

-   -   (c) optionally synthesizing a compound which stimulates        functionality of the receptor in step (b);    -   (d) administering a compound which stimulates functionality of        the receptor in step (b) to a vertebrate; and    -   (e) determining whether the compound increases a level of bone        mass in the vertebrate;        wherein the ability of the test compound to increase a level of        bone mass in the vertebrate is indicative of the test compound        being a compound useful for treating or preventing a condition        characterized by low bone mass or a compound useful for        increasing bone mass in an individual.

In certain embodiments, said determining comprises measuring a level ofbone mass in the vertebrate. In certain embodiments, said measuring alevel of bone mass comprises measuring the level of bone mass using dualenergy X-ray absorbtiometry (DXA). In certain embodiments, saidmeasuring a level of bone mass using DXA comprises measuring a T-scoreusing DXA. In certain embodiments, said measuring a T-score using DXAcomprises measuring a T-score at the hip using DXA. It is expresslycontemplated that said measuring a level of bone mass may comprisemeasuring a level of bone mass using a technique other than DXA, such assingle X-ray absorbtiometry (SXA) (see, e.g., World Health OrganizationTechnical Report Series 921 (2003), Prevention and Management ofOsteoporosis). In certain embodiments, the vertebrate is a mammal. Incertain embodiments, the vertebrate is a non-human vertebrate. Incertain embodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal. In certain embodiments,the vertebrate or mammal is an ovariectomized rat or an ovariectomizedmouse.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising steps (a) and (b) of this firstaspect, and further comprising:

-   -   (c) optionally synthesizing a compound which stimulates        functionality of the receptor in step (b);    -   (d) optionally providing a compound which stimulates        functionality of the receptor in step (b);    -   (e) contacting a compound which stimulates functionality of the        receptor in step (b) in vitro with a vertebrate enteroendocrine        cell or with a cell capable of secreting GIP; and    -   (f) determining whether the compound stimulates GIP secretion        from the vertebrate enteroendocrine cell or from the cell        capable of secreting GIP;        wherein the ability of the test compound to stimulate GIP        secretion from the vertebrate enteroendocrine cell or from the        cell capable of secreting GIP is indicative of the test compound        being a GIP secretagogue, a compound useful for treating or        preventing a condition characterized by low bone mass, or a        compound useful for increasing bone mass in an individual. In        certain embodiments, the vertebrate enteroendocrine cell is a        mammalian enteroendocrine cell. In certain embodiments, the        enteroendocrine cell is a K cell. In certain embodiments, the        enteroendocrine cell comprises tissue derived from the small        intestine. In certain embodiments, the enteroendocrine cell        comprises tissue derived from a K cell rich region of small        intestine. In certain embodiments, the enteroendocrine cell        comprises duodenum or jejunum tissue (see, e.g., Sondhi et al,        Pharmacogenomics J (2006) 6:131-140). In certain embodiments,        the enteroendocrine cell is an enteroendocrine cell line. In        certain embodiments, the cell capable of secreting GIP is a        recombinant cell engineered to be capable of secreting GIP.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising steps (a) and (b) of this firstaspect, and further comprising:

-   -   (c) optionally synthesizing a compound which stimulates        functionality of the receptor in step (b);    -   (d) optionally providing a compound which stimulates        functionality of the receptor in step (b);    -   (e) administering a compound which stimulates functionality of        the receptor in step (b) to a vertebrate; and    -   (f) determining whether the compound increases a GIP level in        the vertebrate;        wherein the ability of the test compound to increase a GIP level        in the vertebrate is indicative of the test compound being a GIP        secretagogue, a compound useful for treating or preventing a        condition characterized by low bone mass, or a compound useful        for increasing bone mass in an individual.

In certain embodiments, the GIP level is blood or plasma concentrationof total GIP. In certain embodiments, the GIP level is blood or plasmaconcentration of bioactive GIP.

In certain embodiments, the vertebrate is a mammal. In certainembodiments, the vertebrate is a non-human vertebrate. In certainembodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising steps (a) and (b) of this firstaspect, and further comprising:

-   -   (c) optionally synthesizing a compound which stimulates        functionality of the receptor in step (b);    -   (d) optionally providing a compound which stimulates        functionality of the receptor in step (b);    -   (e) administering a compound which stimulates functionality of        the receptor in step (b) to a vertebrate; and    -   (f) determining whether the compound increases a level of bone        mass in the vertebrate;        wherein the ability of the test compound to increase a level of        bone mass in the vertebrate is indicative of the test compound        being a compound useful for treating or preventing a condition        characterized by low bone mass or a compound useful for        increasing bone mass in an individual.

In certain embodiments, said determining comprises measuring a level ofbone mass in the individual. In certain embodiments, said measuring alevel of bone mass comprises measuring the level of bone mass using DXA.In certain embodiments, said measuring a level of bone mass using DXAcomprises measuring a T-score using DXA. In certain embodiments, saidmeasuring a T-score using DXA comprises measuring a T-score at the hipusing DXA. It is expressly contemplated that said measuring a level ofbone mass may comprise measuring a level of bone mass using a techniqueother than DXA, such as single X-ray absorbtiometry (SXA) (see, e.g.,World Health Organization Technical Report Series 921 (2003), Preventionand Management of Osteoporosis).

In certain embodiments, the vertebrate is a mammal. In certainembodiments, the vertebrate is a non-human vertebrate. In certainembodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal. In certain embodiments,the vertebrate or mammal is an ovariectomized rat or an ovariectomizedmouse.

In certain embodiments, the identified GIP secretagogue, or theidentified compound useful for treating or preventing a conditioncharacterized by low bone mass, or the identified compound useful forincreasing bone mass in an individual is an agonist of the receptor. Insome embodiments, the agonist is a partial agonist.

In certain embodiments, the G protein-coupled receptor is coupled to a Gprotein. In certain embodiments, activation of the G protein-coupledreceptor increases a level of intracellular cAMP. In certainembodiments, the G protein is Gs.

In certain embodiments, the human DNA sample is human genomic DNA.

In some embodiments, the polymerase chain reaction is reversetranscription-polymerase chain reaction (RT-PCR). RT-PCR techniques arewell known to the skilled artisan. In certain embodiments, the human DNAsample is human cDNA. In certain embodiments, the cDNA is from a humantissue that expresses GPR119. In some embodiments, the human tissue thatexpresses GPR119 is pancreas or pancreatic islet. In certainembodiments, the cDNA is from a human cell type that expresses GPR119.In some embodiments, the cDNA is from a pancreatic beta cell. In someembodiments, the cDNA is from a pancreatic cell line.

In certain embodiments, the G protein-coupled receptor encoded by thepolynucleotide that is amplifiable by polymerase chain reaction is SEQID NO:2 or an allele thereof. In certain embodiments, the Gprotein-coupled receptor encoded by a polynucleotide that is amplifiableby polymerase chain reaction is an allele of SEQ ID NO:2. In certainembodiments, the G protein-coupled receptor encoded by a polynucleotidethat is amplifiable by polymerase chain reaction specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the G protein-coupled receptor encoded by apolynucleotide that is amplifiable by polymerase chain reaction is areceptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the G protein-coupled receptorencoded by a polynucleotide that is amplifiable by polymerase chainreaction exhibits a detectable level of constitutive activity. In someembodiments, the constitutive activity is for increasing a level ofintracellular cAMP. In some embodiments, the constitutive activity isfor causing melanophore cells to undergo pigment dispersion.

In certain embodiments, stringent hybridization conditions comprisehybridization at 42° C. in a solution comprising 50% formamide, 5×SSC(1×SSC=150 mM NaCl, 15 mM trisodium citrate), 50 mM sodium phosphate (pH7.6), 5×Denhardt's solution, 10% dextran sulfate, and 20 μg/mldenatured, sheared salmon sperm DNA, followed by washing at 65° C. in asolution comprising 0.1×SSC. Hybridization techniques are well known tothe skilled artisan.

In certain embodiments, the GPCR encoded by a polynucleotide hybridizingunder conditions of high stringency to the complement of SEQ ID NO: 1 isSEQ ID NO:2 or an allele thereof. In certain embodiments, the GPCRencoded by a polynucleotide hybridizing under conditions of highstringency to the complement of SEQ ID NO: 1 is an allele of SEQ IDNO:2. In certain embodiments, the GPCR encoded by a polynucleotidehybridizing under conditions of high stringency to the complement of SEQID NO: 1 is an ortholog of SEQ ID NO:2. In certain embodiments, the GPCRencoded by a polynucleotide hybridizing under conditions of highstringency to the complement of SEQ ID NO: 1 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the GPCR encoded by a polynucleotide hybridizingunder conditions of high stringency to the complement of SEQ ID NO: 1 isa receptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the GPCR encoded by a polynucleotidehybridizing under conditions of high stringency to the complement of SEQID NO: 1 exhibits a detectable level of constitutive activity. In someembodiments, the constitutive activity is for increasing a level ofintracellular cAMP. In some embodiments, the constitutive activity isfor causing melanophore cells to undergo pigment dispersion.

In certain embodiments, the variant of SEQ ID NO: 2 is a GPCR. Incertain embodiments, the variant of SEQ ID NO: 2 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the variant of SEQ ID NO: 2 is a receptor forwhich(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the variant of SEQ ID NO: 2 exhibitsa detectable level of constitutive activity. In some embodiments, theconstitutive activity is for increasing a level of intracellular cAMP.In some embodiments, the constitutive activity is for causingmelanophore cells to undergo pigment dispersion.

In some embodiments, the G protein-coupled receptor is part of a fusionprotein comprising a G protein. Techniques for making a GPCR:G fusionconstruct are well known to the skilled artisan (see, e.g.,International Application WO 02/42461).

In certain embodiments, the host cell comprises an expression vector,said expression vector comprising a polynucleotide encoding the Gprotein-coupled receptor. In some embodiments, the expression vector ispCMV. This vector was deposited with the American Type CultureCollection (ATCC) on Oct. 13, 1998 (10801 University Blvd., Manassas,Va. 20110-2209 USA) under the provisions of the Budapest Treaty for theInternational Recognition of the Deposit of Microorganisms for thePurpose of Patent Procedure. The DNA was tested by the ATCC anddetermined to be viable. The ATCC has assigned the following depositnumber to pCMV: ATCC #203351. Other suitable expression vectors will bereadily apparent to those of ordinary skill in the art, and a widevariety of expression vectors are commercially available (e.g., fromClontech, Palo Alto, Calif.; Stratagene, La Jolla, Calif.; andInvitrogen, Carlsbad, Calif.).

In some embodiments, the host cell is a vertebrate cell. In someembodiments, the host cell is a mammalian cell. In some embodiments, themammalian host cell is selected from the group consisting of a 293 cell,a 293T cell, a CHO cell, an MCB3901 cell, and a COS-7 cell. In someembodiments, the host cell is a yeast cell. In some embodiments, thehost cell is a melanophore cell. Other suitable host cells will bereadily apparent to those of ordinary skill in the art, and a widevariety of cell lines are available from the American Type CultureCollection, 10801 University Boulevard, Manassas, Va. 20110-2209.

In certain embodiments, said determining is consistent with the Gprotein-coupled receptor being a Gs-coupled receptor.

In some embodiments, said determining is consistent with the Gprotein-coupled receptor being coupled through a promiscuous G protein,such as Gα15 or Gα16, to the phopholipase C pathway. Promiscuous Gproteins are well known to the skilled artisan (see, e.g., Offermanns etal., J Biol Chem (1995) 270:15175-15180). In some embodiments, saiddetermining is consistent with the G protein-coupled receptor beingcoupled through a chimeric G protein, e.g. to the phospholipase Cpathway. Chimeric G proteins are well known to the skilled artisan (see,e.g., Milligan et al., Trends in Pharmaceutical Sciences (1999)20:118-124; and WO 02/42461).

In some embodiments, said determining is through the measurement of alevel of a second messenger.

In some embodiments, said determining is through the measurement of alevel of a second messenger selected from the group consisting of cyclicAMP (cAMP), cyclic GMP (cGMP), inositol 1,4,5-triphosphate (IP₃),diacylglycerol (DAG), MAP kinase activity, MAPK/ERK kinase kinase-1(MEKK1) activity, and Ca²⁺. In some preferred embodiments, the secondmessenger is cAMP. In certain embodiments, a level of intracellular cAMPis increased.

In certain embodiments, said determining is carried out using membranecomprising the G protein-coupled receptor.

In certain embodiments, said determining is through the use of amelanophore assay. In certain embodiments, a level of pigment dispersionis increased.

In some embodiments, said determining is through a reporter assay. Insome embodiments, said reporter assay is CRE-Luc reporter assay.

In some embodiments, said determining is through the measurement of anactivity mediated by increasing a level of intracellular cAMP.

In some embodiments, said determining is through CRE-Luc reporter assay.In certain embodiments, a level of luciferase activity is increased.

In some embodiments, said determining is through the measurement ofGTPγS binding to membrane comprising the G protein-coupled receptor. Incertain embodiments, said GTPγS is labeled with [³⁵S]. In certainembodiments, said GTPγS binding to membrane comprising the GPCR isincreased.

In some embodiments, the test compound is a small molecule. In someembodiments, the test compound is a small molecule, with the provisothat the small molecule is not a polypeptide. In some embodiments, thetest compound is a small molecule, with the proviso that the smallmolecule is not an antibody or an antigen-binding fragment thereof. Insome embodiments, the test compound is a small molecule, with theproviso that the small molecule is not a lipid. In some embodiments, thetest compound is a small molecule, with the proviso that the smallmolecule is not a polypeptide or a lipid. In some embodiments, the testcompound is a polypeptide. In some embodiments, the test compound is apolypeptide, with the proviso that the polypeptide is not an antibody oran antigen-binding fragment thereof. In some embodiments, the testcompound is a lipid. In some embodiments, the test compound is not anantibody or an antigen-binding fragment thereof. In some embodiments,the test compound is an antibody or an antigen-binding fragment thereof.

In some embodiments, the method further comprises the step of optionallydetermining the structure of the GIP secretagogue, the compound usefulfor treating or preventing a condition characterized by low bone mass,or the compound useful for increasing bone mass in an individual.

In some embodiments, the method further comprises the step of optionallyproviding the name or structure of the GIP secretagogue, the compounduseful for treating or preventing a condition characterized by low bonemass, or the compound useful for increasing bone mass in an individual.

In some embodiments, said method further comprises the step ofoptionally producing or synthesizing the GIP secretagogue, the compounduseful for treating or preventing a condition characterized by low bonemass, or the compound useful for increasing bone mass in an individual.

In some embodiments, said method further comprises the step offormulating the GIP secretagogue, the compound useful for treating orpreventing a condition characterized by low bone mass, or the compounduseful for increasing bone mass in an individual into a pharmaceuticalcomposition.

In a second aspect, the invention features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) contacting a compound in vitro with a vertebrate        enteroendocrine cell or with a cell capable of secreting GIP,        said compound having been identified by a method according to        the first aspect; and    -   (b) determining whether the compound stimulates GIP secretion        from the vertebrate enteroendocrine cell or from the cell        capable of secreting GIP;        wherein the ability of the test compound to stimulate GIP        secretion from the vertebrate enteroendocrine cell or from the        cell capable of secreting GIP is further indicative of the test        compound being a GIP secretagogue, a compound useful for        treating or preventing a condition characterized by low bone        mass, or a compound useful for increasing bone mass in an        individual.

In certain embodiments, the vertebrate enteroendocrine cell is amammalian enteroendocrine cell. In certain embodiments, theenteroendocrine cell is a K cell. In certain embodiments, theenteroendocrine cell comprises tissue derived from the small intestine.In certain embodiments, the enteroendocrine cell comprises tissuederived from a K cell rich region of small intestine. In certainembodiments, the enteroendocrine cell comprises duodenum or jejunumtissue (see, e.g., Sondhi et al, Pharmacogenomics J (2006) 6:131-140).In certain embodiments, the enteroendocrine cell is an enteroendocrinecell line. In certain embodiments, the cell capable of secreting GIP isa recombinant cell engineered to be capable of secreting GIP.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) administering a compound to a vertebrate, said compound        having been identified by a method according to the first        aspect; and    -   (b) determining whether the compound increases a GIP level in        the vertebrate;        wherein the ability of the test compound to increase a GIP level        in the vertebrate is further indicative of the test compound        being a GIP secretagogue, a compound useful for treating or        preventing a condition characterized by low bone mass, or a        compound useful for increasing bone mass in an individual.

In certain embodiments, the GIP level is blood or plasma concentrationof total GIP. in certain embodiments, the GIP level is blood or plasmaconcentration of bioactive GIP.

In certain embodiments, the vertebrate is a mammal. In certainembodiments, the vertebrate is a non-human vertebrate. In certainembodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) administering a compound to a vertebrate, said compound        having been identified by a method according to the first        aspect; and    -   (b) determining whether the compound increases a level of bone        mass in the vertebrate;        wherein the ability of the test compound to increase a level of        bone mass in the vertebrate is further indicative of the test        compound being a compound useful for treating or preventing a        condition characterized by low bone mass or a compound useful        for increasing bone mass in an individual.

In certain embodiments, the GIP level is blood or plasma concentrationof total GIP. In certain embodiments, the GIP level is blood or plasmaconcentration of bioactive GIP.

In certain embodiments, the vertebrate is a mammal. In certainembodiments, the vertebrate is a non-human vertebrate. In certainembodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal.

In certain embodiments, said determining comprises measuring a level ofbone mass in the vertebrate. In certain embodiments, said measuring alevel of bone mass comprises measuring the level of bone mass using dualenergy X-ray absorptiometry (DXA). In certain embodiments, saidmeasuring a level of bone mass using DXA comprises measuring a T-scoreusing DXA. In certain embodiments, said measuring a T-score using DXAcomprises measuring a T-score at the hip using DXA. It is expresslycontemplated that said measuring a level of bone mass may comprisemeasuring a level of bone mass using a technique other than DXA, such assingle X-ray absorbtiometry (SXA) (see, e.g., World Health OrganizationTechnical Report Series 921 (2003), Prevention and Management ofOsteoporosis). In certain embodiments, the vertebrate is a mammal. Incertain embodiments, the vertebrate is a non-human vertebrate. Incertain embodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal. In certain embodiments,the vertebrate or mammal is an ovariectomized rat or an ovariectomizedmouse.

In some embodiments, the test compound is a small molecule. In someembodiments, the test compound is a small molecule, with the provisothat the small molecule is not a polypeptide. In some embodiments, thetest compound is a small molecule, with the proviso that the smallmolecule is not an antibody or an antigen-binding fragment thereof. Insome embodiments, the test compound is a small molecule, with theproviso that the small molecule is not a lipid. In some embodiments, thetest compound is a small molecule, with the proviso that the smallmolecule is not a polypeptide or a lipid. In some embodiments, the testcompound is a polypeptide. In some embodiments, the test compound is apolypeptide, with the proviso that the polypeptide is not an antibody oran antigen-binding fragment thereof. In some embodiments, the testcompound is a lipid. In some embodiments, the test compound is not anantibody or an antigen-binding fragment thereof. In some embodiments,the test compound is an antibody or an antigen-binding fragment thereof.

In a third aspect, the invention features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) contacting a GPR119 agonist in vitro with a vertebrate        enteroendocrine cell or with a cell capable of secreting GIP;        and    -   (b) determining whether the GPR119 agonist stimulates GIP        secretion from the vertebrate enteroendocrine cell or from the        cell capable of secreting GIP;        wherein the ability of the GPR119 agonist to stimulate GIP        secretion from the vertebrate enteroendocrine cell or from the        cell capable of secreting GIP is indicative of the GPR119        agonist being a GIP secretagogue, a compound useful for treating        or preventing a condition characterized by low bone mass, or a        compound useful for increasing bone mass in an individual.

In certain embodiments, the vertebrate enteroendocrine cell is amammalian enteroendocrine cell. In certain embodiments, theenteroendocrine cell is a K cell. In certain embodiments, theenteroendocrine cell comprises tissue derived from the small intestine.In certain embodiments, the enteroendocrine cell comprises tissuederived from a K cell rich region of small intestine. In certainembodiments, the enteroendocrine cell comprises duodenum or jejunumtissue (see, e.g., Sondhi et al, Pharmacogenomics J (2006) 6:131-140).In certain embodiments, the enteroendocrine cell is an enteroendocrinecell line. In certain embodiments, the cell capable of secreting GIP isa recombinant cell engineered to be capable of secreting GIP.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) administering a GPR119 agonist to a vertebrate; and    -   (b) determining whether the GPR119 agonist increases a GIP level        in the vertebrate;        wherein the ability of the GPR119 agonist to increase a GIP        level in the vertebrate is indicative of the GPR119 agonist        being a GIP secretagogue, a compound useful for treating or        preventing a condition characterized by low bone mass, or a        compound useful for increasing bone mass in an individual.

In certain embodiments, the GIP level is blood or plasma concentrationof total GIP. In certain embodiments, the GIP level is blood or plasmaconcentration of bioactive GIP.

In certain embodiments, the vertebrate is a mammal. In certainembodiments, the vertebrate is a non-human vertebrate. In certainembodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) administering a GPR119 agonist to a vertebrate; and    -   (b) determining whether the GPR119 agonist increases a level of        bone mass in the vertebrate;        wherein the ability of the GPR119 agonist to increase a level of        bone mass in the vertebrate is indicative of the GPR119 agonist        being a compound useful for treating or preventing a condition        characterized by low bone mass or a compound useful for        increasing bone mass in an individual.

In certain embodiments, the GIP level is blood or plasma concentrationof total GIP. In certain embodiments, the GIP level is blood or plasmaconcentration of bioactive GIP.

In certain embodiments, the vertebrate is a mammal. In certainembodiments, the vertebrate is a non-human vertebrate. In certainembodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal.

In certain embodiments, said determining comprises measuring a level ofbone mass in the vertebrate. In certain embodiments, said measuring alevel of bone mass comprises measuring the level of bone mass using dualenergy X-ray absorptiometry (DXA). In certain embodiments, saidmeasuring a level of bone mass using DXA comprises measuring a T-scoreusing DXA. In certain embodiments, said measuring a T-score using DXAcomprises measuring a T-score at the hip using DXA. It is expresslycontemplated that said measuring a level of bone mass may comprisemeasuring a level of bone mass using a technique other than DXA, such assingle X-ray absorbtiometry (SXA) (see, e.g., World Health OrganizationTechnical Report Series 921 (2003), Prevention and Management ofOsteoporosis). In certain embodiments, the vertebrate is a mammal. Incertain embodiments, the vertebrate is a non-human vertebrate. Incertain embodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal. In certain embodiments,the vertebrate or mammal is an ovariectomized rat or an ovariectomizedmouse.

In certain embodiments, the GPR119 agonist is an agonist of anendogenous GPR119.

In certain embodiments, the GPR119 agonist is an agonist of humanGPR119.

In certain embodiments, the GPR119 agonist is a GPR119 partial agonist.

In certain embodiments, the GPR119 agonist is a selective GPR119agonist.

In certain embodiments, the GPR119 agonist is a small molecule. In someembodiments, the small molecule is not a polypeptide. In someembodiments, the small molecule is not an antibody or an antigen-bindingfragment thereof. In some embodiments, the small molecule is not alipid. In some embodiments, the small molecule is not a polypeptide or alipid.

In certain embodiments, the GPR119 agonist is orally available.

In certain embodiments, the GPR119 agonist has an EC₅₀ value of lessthan about 10 μM, less than about 1 μM, less than about 100 nM, lessthan about 75 nM, less than about 50 nM, less than about 25 nM, lessthan about 15 nM, less than about 10 nM, less than about 5 nM, less thanabout 4 nM, less than about 3 nM, less than about 2 nM, or less thanabout 1 nM. In certain embodiments, the GPR119 agonist has an EC₅₀ valueof less than about 10 μM, less than about 1 μM, less than about 100 nM,less than about 75 nM, less than about 50 nM, less than about 25 nM,less than about 15 nM, less than about 10 nM, less than about 5 nM, lessthan about 4 nM, less than about 3 nM, less than about 2 nM, or lessthan about 1 nM at human GPR119 having SEQ ID NO: 2. In certainembodiments, the GPR119 agonist has an EC₅₀ value of less than about 10μM, less than about 1 μM, less than about 100 nM, less than about 75 nM,less than about 50 nM, less than about 25 nM, less than about 15 nM,less than about 10 nM, less than about 5 nM, less than about 4 nM, lessthan about 3 nM, less than about 2 nM, or less than about 1 nM at humanGPR119 having SEQ ID NO: 2 in adenylyl cyclase assay (exemplary adenylylcyclase assay is provided in Example 7 and in Example 8, infra). Incertain embodiments, the GPR119 agonist has an EC₅₀ value of less thanabout 10 μM, less than about 1 μM, less than about 100 nM, less thanabout 75 nM, less than about 50 nM, less than about 25 nM, less thanabout 15 nM, less than about 10 nM, less than about 5 nM, less thanabout 4 nM, less than about 3 nM, less than about 2 nM, or less thanabout 1 nM at human GPR119 having SEQ ID NO: 2 in melanophore assay(exemplary melanophore assay is provided in Example 9, infra).

Exemplary GPR119 agonists are disclosed, e.g., in InternationalApplication No. PCT/US2004/001267 (published as WO 04/065380);International Application No. PCT/US2004/005555 (published as WO04/076413); International Application No. PCT/US 2004/022327 (publishedas WO 05/007647); International Application No. PCT/US2004/022417(published as WO 05/007658); International Application No.PCT/US2005/019318 (published as WO 2005/121121); InternationalApplication No. PCT/GB2004/050046 (published as WO 2005/061489);International Application No. PCT/US06/00567 (published as WO2006/083491); International Application No. PCT/GB2005/050264 (publishedas WO 2006/067531); International Application No. PCT/GB2005/050265(published as WO 2006/067532); International Application No.PCT/GB2005/050266 (published as WO 2006/070208); InternationalApplication No. PCT/JP02/09350 (published as WO 03/026661);International Application No. PCT/JP2005/018412 (published as WO06/040966); International Application No. PCT/JP2005/019000 (publishedas WO 2006/043490); International Application No. PCT/GB2006/050176(published as WO 2007/003960); International Application No.PCT/GB2006/050177 (published as WO 2007/003961); InternationalApplication No. PCT/GB2006/050178 (published as WO 2007/003962);International Application No. PCT/GB2006/050182 (published as WO2007/003964); and International Application No. PCT/JP02/09350(published as WO 03/026661).

In certain embodiments, the method comprises providing the GPR119agonist.

In certain embodiments, the GPR119 agonist is identifiable by a methodaccording to the first aspect.

In certain embodiments, the method comprises carrying out a methodaccording to the first aspect to identify the GPR119 agonist.

In certain embodiments, the method comprises having identified theGPR119 agonist by a method according to the first aspect.

In a fourth aspect, the invention features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) contacting a 0 protein-coupled receptor with an optionally        labeled known ligand to the receptor in the presence or absence        of a test compound, wherein the G protein-coupled receptor        comprises an amino acid sequence selected from the group        consisting of:        -   (i) amino acids 1-335 of SEQ ID NO:2;        -   (ii) amino acids 2-335 of SEQ ID NO:2;        -   (iii) amino acids 2-335 of SEQ ID NO:2, with the proviso            that the receptor does not comprise the amino acid sequence            of SEQ ID NO:2;        -   (iv) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide that is amplifiable by            polymerase chain reaction (PCR) on a human DNA sample using            specific primers SEQ ID NO:3 and SEQ ID NO:4;        -   (v) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide hybridizing under conditions of            high stringency to the complement of SEQ ID NO:1;        -   (vi) a variant of SEQ ID NO: 2;        -   (vii) the amino acid sequence of (vi) when selected from the            group consisting of:            -   (a′) the amino acid sequence of a G protein-coupled                receptor having at least about 80% identity to SEQ ID                NO: 2; and            -   (b′) the amino acid sequence of a G protein-coupled                receptor comprising at least 20 contiguous amino acids                of SEQ ID NO: 2;        -   (viii) the amino acid sequence of a constitutively active            version of a G protein-coupled receptor having SEQ ID NO: 2;            and        -   (ix) a biologically active fragment of any one of (i) to            (viii); and    -   (b) detecting the complex between said known ligand and said        receptor; and    -   (c) determining whether less of said complex is formed in the        presence of the test compound than in the absence of the test        compound;        wherein said determination is indicative of the test compound        being a GIP secretagogue, a compound useful for treating or        preventing a condition characterized by low bone mass, or a        compound useful for increasing bone mass in an individual.

In certain embodiments, the G protein-coupled receptor comprises theamino acid sequence of a G protein-coupled receptor having at leastabout 80% identity to SEQ ID NO: 2.

In certain embodiments, the receptor comprises the amino acid sequenceof SEQ ID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an allele of SEQID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an ortholog ofSEQ ID NO: 2. In certain embodiments, the variant of SEQ ID NO: 2 is amammalian ortholog of SEQ ID NO: 2.

In certain embodiments, the G protein-coupled receptor is recombinant.

In certain embodiments, the method is a method for identifying GIPsecretagogues.

In certain embodiments, the method is a method for identifying compoundsuseful for preventing or treating a condition characterized by low bonemass

In certain embodiments, the method is a method for identifying compoundsuseful for increasing bone mass in an individual.

In certain embodiments, the known ligand is a ligand or agonist of anendogenous vertebrate, mammalian or human GPR119 receptor. In certainembodiments, the known ligand is a known agonist of an endogenousvertebrate, mammalian or human GPR119 receptor. In certain embodiments,the known ligand is a ligand or agonist of an endogenous human GPR119receptor. In certain embodiments, the known ligand is identical to acompound disclosed in, e.g., in International Application No.PCT/US2004/001267 (published as WO 04/065380); International ApplicationNo. PCT/US2004/005555 (published as WO 04/076413); InternationalApplication No. PCT/US2004/022327 (published as WO 05/007647);International Application No. PCT/US2004/022417 (published as WO05/007658); International Application No. PCT/US2005/019318 (publishedas WO 2005/121121); International Application No. PCT/GB2004/050046(published as WO 2005/061489); International Application No.PCT/US06/00567 (published as WO 2006/083491); International ApplicationNo. PCT/GB2005/050264 (published as WO 2006/067531); InternationalApplication No. PCT/GB2005/050265 (published as WO 2006/067532);International Application No. PCT/GB2005/050266 (published as WO2006/070208); International Application No. PCT/JP02/09350 (published asWO 03/026661); International Application No. PCT/JP2005/018412(published as WO 06/040966); International Application No.PCT/JP2005/019000 (published as WO 2006/043490); InternationalApplication No. PCT/GB2006/050176 (published as WO 2007/003960);International Application No. PCT/GB2006/050177 (published as WO2007/003961); International Application No. PCT/GB2006/050178 (publishedas WO 2007/003962); International Application No. PCT/GB2006/050182(published as WO 2007/003964); or International Application No.PCT/JP02/09350 (published as WO 03/026661). In certain embodiments, theknown ligand is(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the known ligand is an endogenous ligand of anendogenous vertebrate, mammalian, or human GPR119 receptor.

In certain embodiments, the optionally labeled known ligand is a labeledknown ligand. In certain embodiments, the labeled known ligand is aradiolabeled known ligand. Techniques for radiolabeling a compound, suchas for labeling a known ligand of a G protein-coupled receptor of theinvention, are well known to the skilled artisan. See, e.g.,International Application WO 04/065380. Also see, e.g., Example 11,infra.

Techniques for detecting the complex between a G protein-coupledreceptor and a compound known to be a ligand of the G protein-coupledreceptor are well known to the skilled artisan. See, e.g., InternationalApplication WO 04/065380. Also see, e.g., Example 12, infra.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising steps (a) to (c) of this fourthaspect, and further comprising:

-   -   (d) optionally synthesizing a compound in the presence of which        less of said complex is formed in step (c);    -   (e) contacting a compound in the presence of which less of said        complex is formed in step (c) in vitro with a vertebrate        enteroendocrine cell or with a cell capable of secreting GIP;        and    -   (f) determining whether the compound stimulates GIP secretion        from the vertebrate enteroendocrine cell or from the cell        capable of secreting GIP;        wherein the ability of the test compound to stimulate GIP        secretion from the vertebrate enteroendocrine cell or from the        cell capable of secreting GIP is indicative of the test compound        being a GIP secretagogue, a compound useful for treating or        preventing a condition characterized by low bone mass, or a        compound useful for increasing bone mass in an individual. In        certain embodiments, the vertebrate enteroendocrine cell is a        mammalian enteroendocrine cell. In certain embodiments, the        enteroendocrine cell is a K cell. In certain embodiments, the        enteroendocrine cell comprises tissue derived from the small        intestine. In certain embodiments, the enteroendocrine cell        comprises tissue derived from a K cell rich region of small        intestine. In certain embodiments, the enteroendocrine cell        comprises duodenum or jejunum tissue (see, e.g., Sondhi et al,        Pharmacogenomics J (2006) 6:131-140). In certain embodiments,        the enteroendocrine cell is an enteroendocrine cell line. In        certain embodiments, the cell capable of secreting GIP is a        recombinant cell engineered to be capable of secreting GIP.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising steps (a) to (c) of this fourthaspect, and further comprising:

-   -   (d) optionally synthesizing a compound in the presence of which        less of said complex is formed in step (c);    -   (e) administering a compound in the presence of which less of        said complex is formed in step (c) to a vertebrate; and    -   (f) determining whether the compound increases a GIP level in        the vertebrate;        wherein the ability of the test compound to increase a GIP level        in the vertebrate is indicative of the test compound being a GIP        secretagogue, a compound useful for treating or preventing a        condition characterized by low bone mass, or a compound useful        for increasing bone mass in an individual. In certain        embodiments, the vertebrate is a mammal. In certain embodiments,        the vertebrate is a non-human vertebrate. In certain        embodiments, the vertebrate is a non-human mammal. In certain        embodiments, the mammal is a non-human mammal.

The invention additionally features a method for identifying compoundsuseful for preventing or treating a condition characterized by low bonemass or compounds useful for increasing bone mass in an individual,comprising steps (a) to (c) of this fourth aspect, and furthercomprising:

-   -   (d) optionally synthesizing a compound in the presence of which        less of said complex is formed in step (c);    -   (e) administering a compound in the presence of which less of        said complex is formed in step (c) to a vertebrate; and    -   (f) determining whether the compound increases a level of bone        mass in the vertebrate;        wherein the ability of the test compound to increase a level of        bone mass in the vertebrate is indicative of the test compound        being a compound useful for treating or preventing a condition        characterized by low bone mass or a compound useful for        increasing bone mass in an individual.

In certain embodiments, said determining comprises measuring a level ofbone mass in the individual. In certain embodiments, said measuring alevel of bone mass comprises measuring the level of bone mass using DXA.In certain embodiments, said measuring a level of bone mass using DXAcomprises measuring a T-score using DXA. In certain embodiments, saidmeasuring a T-score using DXA comprises measuring a T-score at the hipusing DXA. It is expressly contemplated that said measuring a level ofbone mass may comprise measuring a level of bone mass using a techniqueother than DXA, such as single X-ray absorbtiometry (SXA) (see, e.g.,World Health Organization Technical Report Series 921 (2003), Preventionand Management of Osteoporosis). In certain embodiments, the vertebrateis a mammal. In certain embodiments, the vertebrate is a non-humanvertebrate. In certain embodiments, the vertebrate is a non-humanmammal. In certain embodiments, the mammal is a non-human mammal. Incertain embodiments, the vertebrate or mammal is an ovariectomized rator an ovariectomized mouse.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising steps (a) to (c) of this fourthaspect, and further comprising:

-   -   (d) optionally synthesizing a compound in the presence of which        less of said complex is formed according to step (c);    -   (e) optionally providing a compound in the presence of which        less of said complex is formed according to step (c);    -   (f) contacting a compound in the presence of which less of said        complex is formed according to step (c) in vitro with a        vertebrate enteroendocrine cell or with a cell capable of        secreting GIP; and    -   (g) determining whether the compound stimulates GIP secretion        from the vertebrate enteroendocrine cell or from the cell        capable of secreting GIP;        wherein the ability of the test compound to stimulate GIP        secretion from the vertebrate enteroendocrine cell or from the        cell capable of secreting GIP is indicative of the test compound        being a GIP secretagogue, a compound useful for treating or        preventing a condition characterized by low bone mass, or a        compound useful for increasing bone mass' in an individual. In        certain embodiments, the vertebrate enteroendocrine cell is a        mammalian enteroendocrine cell. In certain embodiments, the        enteroendocrine cell is a K cell. In certain embodiments, the        enteroendocrine cell comprises tissue derived from the small        intestine. In certain embodiments, the enteroendocrine cell        comprises tissue derived from a K cell rich region of small        intestine. In certain embodiments, the enteroendocrine cell        comprises duodenum or jejunum tissue (see, e.g., Sondhi et al,        Pharmacogenomics J (2006) 6:131-140). In certain embodiments,        the enteroendocrine cell is an enteroendocrine cell line. In        certain embodiments, the cell capable of secreting GIP is a        recombinant cell engineered to be capable of secreting GIP.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising steps (a) to (c) of this fourthaspect, and further comprising:

-   -   (d) optionally synthesizing a compound in the presence of which        less of said complex is formed according to step (c);    -   (e) optionally providing a compound in the presence of which        less of said complex is formed according to step (c);    -   (f) administering a compound in the presence of which less of        said complex is formed in step (c) to a vertebrate; and    -   (g) determining whether the compound increases a GIP level in        the vertebrate;        wherein the ability of the test compound to increase a GIP level        in the vertebrate is indicative of the test compound being a GIP        secretagogue, a compound useful for treating or preventing a        condition characterized by low bone mass, or a compound useful        for increasing bone mass in an individual. In certain        embodiments, the vertebrate is a mammal. In certain embodiments,        the vertebrate is a non-human vertebrate. In certain        embodiments, the vertebrate is a non-human mammal. In certain        embodiments, the mammal is a non-human mammal.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising steps (a) to (c) of this fourthaspect, and further comprising:

-   -   (d) optionally synthesizing a compound in the presence of which        less of said complex is formed according to step (c);    -   (e) optionally providing a compound in the presence of which        less of said complex is formed according to step (c);    -   (f) administering a compound in the presence of which less of        said complex is formed in step (c) to a vertebrate; and    -   (g) determining whether the compound increases a level of bone        mass in the vertebrate;        wherein the ability of the test compound to increase a level of        bone mass in the vertebrate is indicative of the test compound        being a compound useful for treating or preventing a condition        characterized by low bone mass or a compound useful for        increasing bone mass in an individual.

In certain embodiments, said determining comprises measuring a level ofbone mass in the individual. In certain embodiments, said measuring alevel of bone mass comprises measuring the level of bone mass using DXA.In certain embodiments, said measuring a level of bone mass using DXAcomprises measuring a T-score using DXA. In certain embodiments, saidmeasuring a T-score using DXA comprises measuring a T-score at the hipusing DXA. It is expressly contemplated that said measuring a level ofbone mass may comprise measuring a level of bone mass using a techniqueother than DXA, such as single X-ray absorbtiometry (SXA) (see, e.g.,World Health Organization Technical Report Series 921 (2003), Preventionand Management of Osteoporosis). In certain embodiments, the vertebrateis a mammal. In certain embodiments, the vertebrate is a non-humanvertebrate. In certain embodiments, the vertebrate is a non-humanmammal. In certain embodiments, the mammal is a non-human mammal. Incertain embodiments, the vertebrate or mammal is an ovariectomized rator an ovariectomized mouse.

In certain embodiments, the human DNA sample is human genomic DNA.

In some embodiments, the polymerase chain reaction is reversetranscription-polymerase chain reaction (RT-PCR). RT-PCR techniques arewell known to the skilled artisan. In certain embodiments, the human DNAsample is human cDNA. In certain embodiments, the cDNA is from a humantissue that expresses GPR119. In some embodiments, the human tissue thatexpresses GPR119 is pancreas or pancreatic islet. In certainembodiments, the cDNA is from a human cell type that expresses GPR119.In some embodiments, the cDNA is from a pancreatic beta cell. In certainembodiments, the cDNA is from a pancreatic cell line.

In certain embodiments, the G protein-coupled receptor encoded by thepolynucleotide that is amplifiable by polymerase chain reaction is SEQID NO:2 or an allele thereof. In certain embodiments, the Gprotein-coupled receptor encoded by a polynucleotide that is amplifiableby polymerase chain reaction is an allele of SEQ ID NO:2. In certainembodiments, the G protein-coupled receptor encoded by a polynucleotidethat is amplifiable by polymerase chain reaction specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the G protein-coupled receptor encoded by apolynucleotide that is amplifiable by polymerase chain reaction is areceptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the G protein-coupled receptorencoded by a polynucleotide that is amplifiable by polymerase chainreaction exhibits a detectable level of constitutive activity. In someembodiments, the constitutive activity is for increasing a level ofintracellular cAMP. In some embodiments, the constitutive activity isfor causing melanophore cells to undergo pigment dispersion.

In certain embodiments, stringent hybridization conditions (e.g.,conditions of high stringency) comprise hybridization at 42° C. in asolution comprising 50% formamide, 5×SSC (1×SSC=150 mM NaCl, 15 mMtrisodium citrate), 50 mM sodium phosphate (pH 7.6), 5×Denhardt'ssolution, 10% dextran sulfate, and 20 μg/ml denatured, sheared salmonsperm DNA, followed by washing at 65° C. in a solution comprising0.1×SSC. Hybridization techniques are well known to the skilled artisan.

In certain embodiments, the GPCR encoded by a polynucleotide hybridizingunder conditions of high stringency to the complement of SEQ ID NO: 1 isSEQ ID NO:2 or an allele thereof. In certain embodiments, the GPCRencoded by a polynucleotide hybridizing under conditions of highstringency to the complement of SEQ ID NO: 1 is an allele of SEQ IDNO:2. In certain embodiments, the GPCR encoded by a polynucleotidehybridizing under conditions of high stringency to the complement of SEQID NO: 1 is an ortholog of SEQ ID NO:2. In certain embodiments, the GPCRencoded by a polynucleotide hybridizing under conditions of highstringency to the complement of SEQ ID NO: 1 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the GPCR encoded by a polynucleotide hybridizingunder conditions of high stringency to the complement of SEQ ID NO: 1 isa receptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the GPCR encoded by a polynucleotidehybridizing under conditions of high stringency to the complement of SEQID NO: 1 exhibits a detectable level of constitutive activity. In someembodiments, the constitutive activity is for increasing a level ofintracellular cAMP. In some embodiments, the constitutive activity isfor causing melanophore cells to undergo pigment dispersion.

In certain embodiments, the variant of SEQ ID NO: 2 is a GPCR. Incertain embodiments, the variant of SEQ ID NO: 2 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the variant of SEQ ID NO: 2 is a receptor forwhich(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the variant of SEQ ID NO: 2 exhibitsa detectable level of constitutive activity. In some embodiments, theconstitutive activity is for increasing a level of intracellular cAMP.In some embodiments, the constitutive activity is for causingmelanophore cells to undergo pigment dispersion.

In some embodiments, the G protein-coupled receptor is part of a fusionprotein comprising a G protein. Techniques for making a GPCR:G fusionconstruct are well known to the skilled artisan (see, e.g.,International Application WO 02/42461).

In certain embodiments, said determining is carried out using a hostcell comprising the G protein-coupled receptor. In certain embodiments,the host cell comprises an expression vector, said expression vectorcomprising a polynucleotide encoding the GPCR. In some embodiments, theexpression vector is pCMV. This vector was deposited with the AmericanType Culture Collection (ATCC) on Oct. 13, 1998 (10801 University Blvd.,Manassas, Va. 20110-2209 USA) under the provisions of the BudapestTreaty for the International Recognition of the Deposit ofMicroorganisms for the Purpose of Patent Procedure. The DNA was testedby the ATCC and determined to be viable. The ATCC has assigned thefollowing deposit number to pCMV: ATCC #203351. Other suitableexpression vectors will be readily apparent to those of ordinary skillin the art, and a wide variety of expression vectors are commerciallyavailable (e.g., from Clontech, Palo Alto, Calif.; Stratagene, La Jolla,Calif.; and Invitrogen, Carlsbad, Calif.).

In some embodiments, the host cell is a vertebrate cell. In someembodiments, the host cell is a mammalian cell. In some embodiments, themammalian host cell is selected from the group consisting of a 293 cell,a 293T cell, a CHO cell, a MCB3901 cell, and a COS-7 cell. In someembodiments, the host cell is a yeast cell. In some embodiments, thehost cell is a melanophore cell. Other suitable host cells will bereadily apparent to those of ordinary skill in the art, and a widevariety of cell lines are available from the American Type CultureCollection, 10801 University Boulevard, Manassas, Va. 20110-2209.

In certain embodiments, said determining is carried out using membranecomprising the G protein-coupled receptor.

In some embodiments, the test compound is a small molecule. In someembodiments, the test compound is a small molecule, with the provisothat the small molecule is not a polypeptide. In some embodiments, thetest compound is a small molecule, with the proviso that the smallmolecule is not an antibody or an antigen-binding fragment thereof. Insome embodiments, the test compound is a small molecule, with theproviso that the small molecule is not a lipid. In some embodiments, thetest compound is a small molecule, with the proviso that the smallmolecule is not a polypeptide or a lipid. In some embodiments, the testcompound is a polypeptide. In some embodiments, the test compound is apolypeptide, with the proviso that the polypeptide is not an antibody oran antigen-binding fragment thereof. In some embodiments, the testcompound is a lipid. In some embodiments, the test compound is not anantibody or an antigen-binding fragment thereof. In some embodiments,the test compound is an antibody or an antigen-binding fragment thereof.

In some embodiments, the method further comprises the step of optionallydetermining the structure of the GIP secretagogue, the compound usefulfor treating or preventing a condition characterized by low bone mass,or the compound useful for increasing bone mass in an individual.

In some embodiments, the method further comprises the step of optionallyproviding the name or structure of the GIP secretagogue, the compounduseful for treating or preventing a condition characterized by low bonemass, or the compound useful for increasing bone mass in an individual.

In some embodiments, said method further comprises the step ofoptionally producing or synthesizing the GIP secretagogue, the compounduseful for treating or preventing a condition characterized by low bonemass, or the compound useful for increasing bone mass in an individual.

In some embodiments, said method further comprises the step offormulating the GIP secretagogue, the compound useful for treating orpreventing a condition characterized by low bone mass, or the compounduseful for increasing bone mass in an individual into a pharmaceuticalcomposition.

In a fifth aspect, the invention features a method of screening testcompounds to identify a GIP secretagogue, a compound for treating orpreventing a condition characterized by low bone mass, or a compound forincreasing bone mass in an individual, which is characterized by using aG protein-coupled receptor comprising an amino acid sequence selectedfrom the group consisting of

-   -   (a) amino acids 1-335 of SEQ ID NO: 2;    -   (b) amino acids 2-335 of SEQ ID NO: 2;    -   (c) amino acids 2-335 of SEQ ID NO: 2, wherein the GPCR does not        comprise the amino acid sequence of SEQ ID NO: 2;    -   (d) the amino acid sequence of a G protein-coupled receptor        encoded by a polynucleotide that is amplifiable by polymerase        chain reaction (PCR) on a human DNA sample using specific        primers SEQ ID NO: 3 and SEQ ID NO: 4;    -   (e) the amino acid sequence of a G protein-coupled receptor        encoded by a polynucleotide hybridizing under conditions of high        stringency to the complement of SEQ ID NO: 1;    -   (f) a variant of SEQ ID NO: 2;    -   (g) the amino acid sequence of (f) when selected from the group        consisting of        -   (i) the amino acid sequence of a G protein-coupled receptor            having at least about 80% identity to SEQ ID NO: 2; and        -   (ii) the amino acid sequence of a G protein-coupled receptor            comprising at least 20 continguous amino acids of SEQ ID NO:            2;    -   (h) the amino acid sequence of a constitutively active version        of a G protein-coupled receptor having SEQ ID NO: 2; and    -   (i) a biologically active fragment of any one of any one of (a)        to (h).

In certain embodiments, the G protein-coupled receptor comprises theamino acid sequence of a G protein-coupled receptor having at leastabout 80% identity to SEQ ID NO: 2.

In certain embodiments, the receptor comprises the amino acid sequenceof SEQ ID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an allele of SEQID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an ortholog ofSEQ ID NO: 2. In certain embodiments, the variant of SEQ ID NO: 2 is amammalian ortholog of SEQ ID NO: 2.

In certain embodiments, the G protein-coupled receptor is recombinant.

In certain embodiments, the method comprises identifying an agonist ofthe receptor.

In certain embodiments, the method comprises identifying a partialagonist of the receptor.

In some embodiments, said method further comprises the step offormulating the GIP secretagogue, the compound useful for treating orpreventing a condition characterized by low bone mass, or the compounduseful for increasing bone mass in an individual into a pharmaceuticalcomposition.

In a sixth aspect, the invention features a method comprising, havingidentified a GIP secretagogue, a compound for treating or preventing acondition characterized by low bone mass, or a compound for increasingbone mass in an individual according to the first aspect, the secondaspect, the third aspect, the fourth aspect or the fifth aspect,formulating said GIP secretagogue, said compound for treating orpreventing a condition characterized by low bone mass, or said compoundfor increasing bone mass in an individual into a pharmaceuticalcomposition.

In a seventh aspect, the invention features use of a G protein-coupledreceptor to screen test compounds as GIP secretagogues, compounds fortreating or preventing a condition characterized by low bone mass, orcompounds for increasing bone mass in an individual, wherein the Gprotein-coupled receptor comprises an amino acid sequence selected fromthe group consisting of:

-   -   (a) amino acids 1-335 of SEQ ID NO: 2;    -   (b) amino acids 2-335 of SEQ ID NO: 2;    -   (c) amino acids 2-335 of SEQ ID NO: 2, wherein the GPCR does not        comprise the amino acid sequence of SEQ ID NO: 2;    -   (d) the amino acid sequence of a G protein-coupled receptor        encoded by a polynucleotide that is amplifiable by polymerase        chain reaction (PCR) on a human DNA sample using specific        primers SEQ ID NO: 3 and SEQ ID NO: 4;    -   (e) the amino acid sequence of a G protein-coupled receptor        encoded by a polynucleotide hybridizing under conditions of high        stringency to the complement of SEQ ID NO: 1;    -   (f) a variant of SEQ ID NO: 2;    -   (g) the amino acid sequence of (f) when selected from the group        consisting of:        -   (i) the amino acid sequence of a G protein-coupled receptor            having at least about 80% identity to SEQ ID NO: 2; and        -   (ii) the amino acid sequence of a G protein-coupled receptor            comprising at least 20 contiguous amino acids of SEQ ID NO:            2;    -   (h) the amino acid sequence of a constitutively active version        of a G protein-coupled receptor having SEQ ID NO: 2; and    -   (i) a biologically active fragment of any one of any one of (a)        to (h).

In certain embodiments, the G protein-coupled receptor comprises theamino acid sequence of a G protein-coupled receptor having at leastabout 80% identity to SEQ ID NO: 2.

In certain embodiments, the receptor comprises the amino acid sequenceof SEQ ID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an allele of SEQID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an ortholog ofSEQ ID NO: 2. In certain embodiments, the variant of SEQ ID NO: 2 is amammalian ortholog of SEQ ID NO: 2.

In certain embodiments, the receptor is recombinant.

In certain embodiments, the test compound is a small molecule.

In certain embodiments, the test compound is a GPR119 agonist.

In certain embodiments, the GPR119 agonist is an agonist of anendogenous GPR119.

In certain embodiments, the GPR119 agonist is an agonist of humanGPR119.

In certain embodiments, the GPR119 agonist is a GPR119 partial agonist.

In certain embodiments, the GPR119 agonist is a selective GPR119agonist.

In certain embodiments, the GPR119 agonist is a small molecule.

In certain embodiments, the GPR119 agonist is orally available.

In certain embodiments, the GPR119 agonist has an EC₅₀ value of lessthan about 10 μM, less than about 1 μM, less than about 100 nM, lessthan about 75 nM, less than about 50 nM, less than about 25 nM, lessthan about 15 nM, less than about 10 nM, less than about 5 nM, less thanabout 4 nM, less than about 3 nM, less than about 2 nM, or less thanabout 1 nM. In certain embodiments, the GPR119 agonist has an EC₅₀ valueof less than about 10 μM, less than about 1 μM, less than about 100 nM,less than about 75 nM, less than about 50 nM, less than about 25 nM,less than about 15 nM, less than about 10 nM, less than about 5 nM, lessthan about 4 nM, less than about 3 nM, less than about 2 nM, or lessthan about 1 nM at human GPR119 having SEQ ID NO: 2. In certainembodiments, the GPR119 agonist has an EC₅₀ value of less than about 10μN, less than about 1 μM less than about 100 nM, less than about 75 nM,less than about 50 nM, less than about 25 nM, less than about 15 nM,less than about 10 nM, less than about 5 nM, less than about 4 nM, lessthan about 3 nM, less than about 2 nM, or less than about 1 nM at humanGPR119 having SEQ ID NO: 2 in adenylyl cyclase assay (exemplary adenylylcyclase assay is provided in Example 7 and in Example 8, infra). Incertain embodiments, the GPR119 agonist has an EC₅₀ value of less thanabout 10 μM, less than about 1 μM, less than about 100 nM, less thanabout 75 nM, less than about 50 nM, less than about 25 nM, less thanabout 15 nM, less than about 10 nM, less than about 5 nM, less thanabout 4 nM, less than about 3 nM, less than about 2 nM, or less thanabout 1 nM at human GPR119 having SEQ ID NO: 2 in melanophore assay(exemplary melanophore assay is provided in Example 9, infra).

Exemplary GPR119 agonists are disclosed, e.g., in InternationalApplication No. PCT/US2004/001267 (published as WO 04/065380);International Application No. PCT/US2004/005555 (published as WO04/076413); International Application No. PCT/US2004/022327 (publishedas WO 05/007647); International Application No. PCT/US2004/022417(published as WO 05/007658); International Application No.PCT/US2005/019318 (published as WO 2005/121121); InternationalApplication No. PCT/GB2004/050046 (published as WO 2005/061489);International Application No. PCT/US06/00567 (published as WO2006/083491); International Application No. PCT/GB2005/050264 (publishedas WO 2006/067531); International Application No. PCT/GB2005/050265(published as WO 2006/067532); International Application No.PCT/GB2005/050266 (published as WO 2006/070208); InternationalApplication No. PCT/JP02/09350 (published as WO 03/026661);International Application No. PCT/JP2005/018412 (published as WO06/040966); International Application No. PCT/JP2005/019000 (publishedas WO 2006/043490); International Application No. PCT/GB2006/050176(published as WO 2007/003960); International Application No.PCT/GB2006/050177 (published as WO 2007/003961); InternationalApplication No. PCT/GB2006/050178 (published as WO 2007/003962);International Application No. PCT/GB2006/050182 (published as WO2007/003964); and International Application No. PCT/JP02/09350(published as WO 03/026661).

In an eighth aspect, the invention features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) contacting a compound which stimulates functionality of a G        protein-coupled receptor, wherein said G protein-coupled        receptor comprises an amino acid sequence selected from the        group consisting of:        -   (i) amino acids 1-335 of SEQ ID NO:2;        -   (ii) amino acids 2-335 of SEQ ID NO:2;        -   (iii) amino acids 2-335 of SEQ ID NO:2, with the proviso            that the G protein-coupled receptor does not comprise the            amino acid sequence of SEQ ID NO:2;        -   (iv) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide that is amplifiable by            polymerase chain reaction (PCR) on a human DNA sample using            specific primers SEQ ID NO:3 and SEQ ID NO:4;        -   (v) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide hybridizing under conditions of            high stringency to the complement of SEQ ID NO: 1;        -   (vi) a variant of SEQ ID NO: 2;        -   (vii) the amino acid sequence of (vi) when selected from the            group consisting of:            -   (a′) the amino acid sequence of a G protein-coupled                receptor having at least about 80% identity to SEQ ID                NO: 2; and            -   (b′) an amino acid sequence of a G protein-coupled                receptor comprising at least 20 contiguous amino acids                of SEQ ID NO: 2;        -   (viii) the amino acid sequence of a constitutively active            version of a G protein-coupled receptor having SEQ ID NO: 2;            and        -   (ix) a biologically active fragment of any one of (i) to            (viii); in vitro with a vertebrate enteroendocrine cell or            with a cell capable of secreting GIP, said compound having            been determined or identified by a method according to the            first aspect; and    -   (b) determining whether the compound stimulates GIP secretion        from the vertebrate enteroendocrine cell or from the cell        capable of secreting GIP;        wherein the ability of the test compound to stimulate GIP        secretion from the vertebrate enteroendocrine cell or from the        cell capable of secreting GIP is further indicative of the test        compound being a GIP secretagogue, a compound useful for        treating or preventing a condition characterized by low bone        mass, or a compound useful for increasing bone mass in an        individual.

In certain embodiments, the G protein-coupled receptor comprises theamino acid sequence of a G protein-coupled receptor having at leastabout 80% identity to SEQ ID NO: 2.

In certain embodiments, the receptor comprises the amino acid sequenceof SEQ ID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an allele of SEQID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an ortholog ofSEQ ID NO: 2. In certain embodiments, the variant of SEQ ID NO: 2 is amammalian ortholog of SEQ ID NO: 2.

In certain embodiments, the G protein-coupled receptor is recombinant.

In certain embodiments, the vertebrate enteroendocrine cell is amammalian enteroendocrine cell. In certain embodiments, theenteroendocrine cell is a K cell. In certain embodiments, theenteroendocrine cell comprises tissue derived from the small intestine.In certain embodiments, the enteroendocrine cell comprises tissuederived from a K cell rich region of small intestine. In certainembodiments, the enteroendocrine cell comprises duodenum or jejunumtissue (see, e.g., Sondhi et al, Pharmacogenomics J (2006) 6:131-140).In certain embodiments, the enteroendocrine cell is an enteroendocrinecell line. In certain embodiments, the cell capable of secreting GIP isa pancreatic cell. See, e.g., Xie et al, Bone 2007 as relates topancreatic expression of GIP. In certain embodiments, the cell capableof secreting GIP is a recombinant cell engineered to be capable ofsecreting GIP.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

(a) administering to a vertebrate a compound which stimulatesfunctionality of a G protein-coupled receptor, wherein said Gprotein-coupled receptor comprises an amino acid sequence selected fromthe group consisting of:

-   -   (i) amino acids 1-335 of SEQ ID NO:2;    -   (ii) amino acids 2-335 of SEQ ID NO:2;    -   (iii) amino acids 2-335 of SEQ ID NO:2, with the proviso that        the G protein-coupled receptor does not comprise the amino acid        sequence of SEQ ID NO:2;    -   (iv) the amino acid sequence of a G protein-coupled receptor        encoded by a polynucleotide that is amplifiable by polymerase        chain reaction (PCR) on a human DNA sample using specific        primers SEQ ID NO:3 and SEQ ID NO:4;    -   (viii) the amino acid sequence of a G protein-coupled receptor        encoded by a polynucleotide hybridizing under conditions of high        stringency to the complement of SEQ ID NO: 1;    -   (ix) a variant of SEQ ID NO: 2;    -   (x) the amino acid sequence of (vi) when selected from the group        consisting of:        -   (a′) the amino acid sequence of a G protein-coupled receptor            having at least about 80% identity to SEQ ID NO: 2; and        -   (b′) an amino acid sequence of a G protein-coupled receptor            comprising at least 20 contiguous amino acids of SEQ ID NO:            2;    -   (viii) the amino acid sequence of a constitutively active        version of a G protein-coupled receptor having SEQ ID NO: 2; and    -   (ix) a biologically active fragment of any one of (i) to (viii);        said compound having been determined or identified by a method        according to the first aspect; and

(b) determining whether the compound increases a GIP level in thevertebrate;

wherein the ability of the test compound to increase a GIP level in thevertebrate is further indicative of the test compound being a GIPsecretagogue, a compound useful for treating or preventing a conditioncharacterized by low bone mass, or a compound useful for increasing bonemass in an individual.

In certain embodiments, the G protein-coupled receptor comprises theamino acid sequence of a G protein-coupled receptor having at leastabout 80% identity to SEQ ID NO: 2.

In certain embodiments, the receptor comprises the amino acid sequenceof SEQ ID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an allele of SEQID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an ortholog ofSEQ ID NO: 2. In certain embodiments, the variant of SEQ ID NO: 2 is amammalian ortholog of SEQ ID NO: 2.

In certain embodiments, the G protein-coupled receptor is recombinant.

In certain embodiments, the GIP level is blood or plasma or serumconcentration of total GIP. In certain embodiments, the GIP level isblood or plasma or serum concentration of bioactive GIP.

In certain embodiments, the vertebrate is a mammal. In certainembodiments, the vertebrate is a non-human vertebrate. In certainembodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for treating or preventing a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) administering to a vertebrate a compound which stimulates        functionality of a G protein-coupled receptor, wherein said G        protein-coupled receptor comprises an amino acid sequence        selected from the group consisting of:        -   (i) amino acids 1-335 of SEQ ID NO:2;        -   (ii) amino acids 2-335 of SEQ ID NO:2;        -   (iii) amino acids 2-335 of SEQ ID NO:2, with the proviso            that the G protein-coupled receptor does not comprise the            amino acid sequence of SEQ ID NO:2;        -   (iv) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide that is amplifiable by            polymerase chain reaction (PCR) on a human DNA sample using            specific primers SEQ ID NO:3 and SEQ ID NO:4;        -   (xi) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide hybridizing under conditions of            high stringency to the complement of SEQ ID NO: 1;        -   (xii) a variant of SEQ ID NO: 2;        -   (xiii) the amino acid sequence of (vi) when selected from            the group consisting of:            -   (a′) the amino acid sequence of a G protein-coupled                receptor having at least about 80% identity to SEQ ID                NO: 2; and            -   (b′) an amino acid sequence of a G protein-coupled                receptor comprising at least 20 contiguous amino acids                of SEQ ID NO: 2;        -   (viii) the amino acid sequence of a constitutively active            version of a G protein-coupled receptor having SEQ ID NO: 2;            and        -   (ix) a biologically active fragment of any one of (i) to            (viii); said compound having been determined or identified            by a method according to the first aspect; and    -   (b) determining whether the compound increases a level of bone        mass in the vertebrate;        wherein the ability of the test compound to increase a level of        bone mass in the vertebrate is further indicative of the test        compound being a compound useful for treating or preventing a        condition characterized by low bone mass or a compound useful        for increasing bone mass in an individual.

In certain embodiments, the G protein-coupled receptor comprises theamino acid sequence of a G protein-coupled receptor having at leastabout 80% identity to SEQ ID NO: 2.

In certain embodiments, the receptor comprises the amino acid sequenceof SEQ ID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an allele of SEQID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an ortholog ofSEQ ID NO: 2. In certain embodiments, the variant of SEQ ID NO: 2 is amammalian ortholog of SEQ ID NO: 2.

In certain embodiments, the G protein-coupled receptor is recombinant.

In certain embodiments, the vertebrate is a mammal. In certainembodiments, the vertebrate is a non-human vertebrate. In certainembodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal. In certain embodiments,the vertebrate or mammal is an ovariectomized rat or an ovariectomizedmouse.

In certain embodiments, said determining comprises measuring a level ofbone mass in the vertebrate. In certain embodiments, said measuring alevel of bone mass comprises measuring the level of bone mass using dualenergy X-ray absorptiometry (DXA). In certain embodiments, saidmeasuring a level of bone mass using DXA comprises measuring a T-scoreusing DXA. In certain embodiments, said measuring a T-score using DXAcomprises measuring a T-score at the hip using DXA. It is expresslycontemplated that said measuring a level of bone mass may comprisemeasuring a level of bone mass using a technique other than DXA, such assingle X-ray absorbtiometry (SXA) (see, e.g., World Health OrganizationTechnical Report Series 921 (2003), Prevention and Management ofOsteoporosis).

In certain embodiments, the human DNA sample is human genomic DNA.

In some embodiments, the polymerase chain reaction is reversetranscription-polymerase chain reaction (RT-PCR). RT-PCR techniques arewell known to the skilled artisan. In certain embodiments, the human DNAsample is human cDNA. In certain embodiments, the cDNA is from a humantissue that expresses GPR119. In some embodiments, the human tissue thatexpresses GPR119 is pancreas or pancreatic islet. In certainembodiments, the cDNA is from a human cell type that expresses GPR119.In some embodiments, the cDNA is from a pancreatic beta cell. In certainembodiments, the cDNA is from a pancreatic cell line.

In certain embodiments, the G protein-coupled receptor encoded by thepolynucleotide that is amplifiable by polymerase chain reaction is SEQID NO:2 or an allele thereof. In certain embodiments, the Gprotein-coupled receptor encoded by a polynucleotide that is amplifiableby polymerase chain reaction is an allele of SEQ ID NO:2. In certainembodiments, the G protein-coupled receptor encoded by a polynucleotidethat is amplifiable by polymerase chain reaction specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the G protein-coupled receptor encoded by apolynucleotide that is amplifiable by polymerase chain reaction is areceptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the G protein-coupled receptorencoded by a polynucleotide that is amplifiable by polymerase chainreaction exhibits a detectable level of constitutive activity. In someembodiments, the constitutive activity is for increasing a level ofintracellular cAMP. In some embodiments, the constitutive activity isfor causing melanophore cells to undergo pigment dispersion.

In certain embodiments, stringent hybridization conditions (e.g.,conditions of high stringency) comprise hybridization at 42° C. in asolution comprising 50% formamide, 5×SSC (1×SSC=150 mM NaCl, 15 mMtrisodium citrate), 50 mM sodium phosphate (pH 7.6), 5×Denhardt'ssolution, 10% dextran sulfate, and 20 μg/ml denatured, sheared salmonsperm DNA, followed by washing at 65° C. in a solution comprising0.1×SSC. Hybridization techniques are well known to the skilled artisan.

In certain embodiments, the GPCR encoded by a polynucleotide hybridizingunder conditions of high stringency to the complement of SEQ ID NO: 1 isSEQ ID NO:2 or an allele thereof. In certain embodiments, the GPCRencoded by a polynucleotide hybridizing under conditions of highstringency to the complement of SEQ ID NO: 1 is an allele of SEQ IDNO:2. In certain embodiments, the GPCR encoded by a polynucleotidehybridizing under conditions of high stringency to the complement of SEQID NO: 1 is an ortholog of SEQ ID NO:2. In certain embodiments, the GPCRencoded by a polynucleotide hybridizing under conditions of highstringency to the complement of SEQ ID NO: 1 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the GPCR encoded by a polynucleotide hybridizingunder conditions of high stringency to the complement of SEQ ID NO: 1 isa receptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the GPCR encoded by a polynucleotidehybridizing under conditions of high stringency to the complement of SEQID NO: 1 exhibits a detectable level of constitutive activity. In someembodiments, the constitutive activity is for increasing a level ofintracellular cAMP. In some embodiments, the constitutive activity isfor causing melanophore cells to undergo pigment dispersion.

In certain embodiments, the variant of SEQ ID NO: 2 is a GPCR. Incertain embodiments, the variant of SEQ ID NO: 2 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the variant of SEQ ID NO: 2 is a receptor forwhich(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the variant of SEQ ID NO: 2 exhibitsa detectable level of constitutive activity. In some embodiments, theconstitutive activity is for increasing a level of intracellular cAMP.In some embodiments, the constitutive activity is for causingmelanophore cells to undergo pigment dispersion.

In some embodiments, the G protein-coupled receptor is part of a fusionprotein comprising a G protein. Techniques for making a GPCR:G fusionconstruct are well known to the skilled artisan (see, e.g.,International Application WO 02/42461).

In some embodiments, the compound which stimulates functionality of a Gprotein-coupled receptor is a small molecule. In some embodiments, thecompound which stimulates functionality of a G protein-coupled receptoris a small molecule, with the proviso that the small molecule is not apolypeptide. In some embodiments, the compound which stimulatesfunctionality of a G protein-coupled receptor is a small molecule, withthe proviso that the small molecule is not an antibody or anantigen-binding fragment thereof. In some embodiments, the compoundwhich stimulates functionality of a G protein-coupled receptor is asmall molecule, with the proviso that the small molecule is not a lipid.In some embodiments, the compound which stimulates functionality of a Gprotein-coupled receptor is a small molecule, with the proviso that thesmall molecule is not a polypeptide or a lipid. In some embodiments, thecompound which stimulates functionality of a G protein-coupled receptoris a polypeptide. In some embodiments, the compound which stimulatesfunctionality of a G protein-coupled receptor is a polypeptide, with theproviso that the polypeptide is not an antibody or an antigen-bindingfragment thereof. In some embodiments, the compound which stimulatesfunctionality of a G protein-coupled receptor is a lipid. In someembodiments, the compound which stimulates functionality of a Gprotein-coupled receptor is not an antibody or an antigen-bindingfragment thereof. In some embodiments, the compound which stimulatesfunctionality of a G protein-coupled receptor is an antibody or anantigen-binding fragment thereof.

In some embodiments, the method further comprises the step of optionallydetermining the structure of the GIP secretagogue, the compound usefulfor treating or preventing a condition characterized by low bone mass,or the compound useful for increasing bone mass in an individual.

In some embodiments, the method further comprises the step of optionallyproviding the name or structure of the GIP secretagogue, the compounduseful for treating or preventing a condition characterized by low bonemass, or the compound useful for increasing bone mass in an individual.

In some embodiments, said method further comprises the step ofoptionally producing or synthesizing the GIP secretagogue, the compounduseful for treating or preventing a condition characterized by low bonemass, or the compound useful for increasing bone mass in an individual.

In some embodiments, said method further comprises the step offormulating the GIP secretagogue, the compound useful for treating orpreventing a condition characterized by low bone mass, or the compounduseful for increasing bone mass in an individual as a pharmaceutical.

In some embodiments, said method further comprises the step offormulating the GIP secretagogue, the compound useful for treating orpreventing a condition characterized by low bone mass, or the compounduseful for increasing bone mass in an individual into a pharmaceuticalcomposition.

In a ninth aspect, the invention features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) contacting a compound in the presence of which less of a        complex between a G protein-coupled receptor and an optionally        labelled known ligand to the receptor is formed than in the        absence of the compound, wherein the G protein-coupled receptor        comprises an amino acid sequence selected from the group        consisting of:        -   (i) amino acids 1-335 of SEQ ID NO:2;        -   (ii) amino acids 2-335 of SEQ ID NO:2;        -   (iii) amino acids 2-335 of SEQ ID NO:2, with the proviso            that the receptor does not comprise the amino acid sequence            of SEQ ID NO:2;        -   (iv) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide that is amplifiable by            polymerase chain reaction (PCR) on a human DNA sample using            specific primers SEQ ID NO:3 and SEQ ID NO:4;        -   (v) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide hybridizing under conditions of            high stringency to the complement of SEQ ID NO:1;        -   (vi) a variant of SEQ ID NO: 2;        -   (vii) the amino acid sequence of (vi) when selected from the            group consisting of:            -   (a′) the amino acid sequence of a G protein-coupled                receptor having at least about 80% identity to SEQ ID                NO: 2; and            -   (b′) the amino acid sequence of a G protein-coupled                receptor comprising at least 20 contiguous amino acids                of SEQ ID NO: 2;        -   (viii) the amino acid sequence of a constitutively active            version of a G protein-coupled receptor having SEQ ID NO: 2;            and        -   (ix) a biologically active fragment of any one of (i) to            (viii); in vitro with a vertebrate enteroendocrine cell or            with a cell capable of secreting GIP, said compound having            been determined or identified by a method according to the            fourth aspect; and    -   (b) determining whether the compound stimulates GIP secretion        from the vertebrate enteroendocrine cell or from the cell        capable of secreting GIP;        wherein the ability of the test compound to stimulate GIP        secretion from the vertebrate enteroendocrine cell or from the        cell capable of secreting GIP is further indicative of the test        compound being a GIP secretagogue, a compound useful for        treating or preventing a condition characterized by low bone        mass, or a compound useful for increasing bone mass in an        individual.

In certain embodiments, the G protein-coupled receptor comprises theamino acid sequence of a G protein-coupled receptor having at leastabout 80% identity to SEQ ID NO: 2.

In certain embodiments, the receptor comprises the amino acid sequenceof SEQ ID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an allele of SEQID NO: 2.

In certain embodiments, the variant of SEQ ID NO: 2 is an ortholog ofSEQ ID NO: 2. In certain embodiments, the variant of SEQ ID NO: 2 is amammalian ortholog of SEQ ID NO: 2.

In certain embodiments, the G protein-coupled receptor is recombinant.

In certain embodiments, the vertebrate enteroendocrine cell is amammalian enteroendocrine cell. In certain embodiments, theenteroendocrine cell is a K cell. In certain embodiments, theenteroendocrine cell comprises tissue derived from the small intestine.In certain embodiments, the enteroendocrine cell comprises tissuederived from a K cell rich region of small intestine. In certainembodiments, the enteroendocrine cell comprises duodenum or jejunumtissue (see, e.g., Sondhi et al, Pharmacogenomics J (2006) 6:131-140).In certain embodiments, the enteroendocrine cell is an enteroendocrinecell line. In certain embodiments, the cell capable of secreting GIP isa pancreatic cell. See, e.g., Xie et al, Bone 2007 as relates topancreatic expression of GIP. In certain embodiments, the cell capableof secreting GIP is a recombinant cell engineered to be capable ofsecreting GIP.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of:

-   -   (a) administering a compound to a vertebrate, wherein in the        presence of said compound less of a complex between a G        protein-coupled receptor and an optionally labelled known ligand        to the receptor is formed than in the absence of the compound,        wherein the G protein-coupled receptor comprises an amino acid        sequence selected from the group consisting of:        -   (i) amino acids 1-335 of SEQ ID NO:2;        -   (ii) amino acids 2-335 of SEQ ID NO:2;        -   (iii) amino acids 2-335 of SEQ ID NO:2, with the proviso            that the receptor does not comprise the amino acid sequence            of SEQ ID NO:2;        -   (iv) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide that is amplifiable by            polymerase chain reaction (PCR) on a human DNA sample using            specific primers SEQ ID NO:3 and SEQ ID NO:4;        -   (viii) the amino acid sequence of a G protein-coupled            receptor encoded by a polynucleotide hybridizing under            conditions of high stringency to the complement of SEQ ID            NO:1;        -   (ix) a variant of SEQ ID NO: 2;        -   (x) the amino acid sequence of (vi) when selected from the            group consisting of:            -   (a′) the amino acid sequence of a G protein-coupled                receptor having at least about 80% identity to SEQ ID                NO: 2; and            -   (b′) the amino acid sequence of a G protein-coupled                receptor comprising at least 20 contiguous amino acids                of SEQ ID NO: 2;        -   (viii) the amino acid sequence of a constitutively active            version of a G protein-coupled receptor having SEQ ID NO: 2;            and        -   (ix) a biologically active fragment of any one of (i) to            (viii);        -   said compound having been determined or identified by a            method according to the fourth aspect; and

(b) determining whether the compound increases a GIP level in thevertebrate;

wherein the ability of the test compound to increase a GIP level in thevertebrate is further indicative of the test compound being a GIPsecretagogue, a compound useful for treating or preventing a conditioncharacterized by low bone mass, or a compound useful for increasing bonemass in an individual.

In certain embodiments, the vertebrate is a mammal. In certainembodiments, the vertebrate is a non-human vertebrate. In certainembodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal.

The invention additionally features a method for identifying GIPsecretagogues, compounds useful for preventing or treating a conditioncharacterized by low bone mass, or compounds useful for increasing bonemass in an individual, comprising the steps of

-   -   (a) administering a compound to a vertebrate, wherein in the        presence of said compound less of a complex between a G        protein-coupled receptor and an optionally labelled known ligand        to the receptor is formed than in the absence of the compound,        wherein the G protein-coupled receptor comprises an amino acid        sequence selected from the group consisting of        -   (i) amino acids 1-335 of SEQ ID NO:2;        -   (ii) amino acids 2-335 of SEQ ID NO:2;        -   (iii) amino acids 2-335 of SEQ ID NO:2, with the proviso            that the receptor does not comprise the amino acid sequence            of SEQ ID NO:2;        -   (iv) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide that is amplifiable by            polymerase chain reaction (PCR) on a human DNA sample using            specific primers SEQ ID NO:3 and SEQ ID NO:4;        -   (xi) the amino acid sequence of a G protein-coupled receptor            encoded by a polynucleotide hybridizing under conditions of            high stringency to the complement of SEQ ID NO:1;        -   (xii) a variant of SEQ ID NO: 2;        -   (xiii) the amino acid sequence of (vi) when selected from            the group consisting of:            -   (a′) the amino acid sequence of a G protein-coupled                receptor having at least about 80% identity to SEQ ID                NO: 2; and            -   (b′) the amino acid sequence of a G protein-coupled                receptor comprising at least 20 contiguous amino acids                of SEQ ID NO: 2;        -   (viii) the amino acid sequence of a constitutively active            version of a G protein-coupled receptor having SEQ ID NO: 2;            and        -   (ix) a biologically active fragment of any one of (i) to            (viii); said compound having been determined or identified            by a method according to the fourth aspect; and    -   (b) determining whether the compound increases a level of bone        mass in the vertebrate;        wherein the ability of the test compound to increase a level of        bone mass in the vertebrate is further indicative of the test        compound being a GIP secretagogue, a compound useful for        treating or preventing a condition characterized by low bone        mass, or a compound useful for increasing bone mass in an        individual.

In certain embodiments, the vertebrate is a mammal. In certainembodiments, the vertebrate is a non-human vertebrate. In certainembodiments, the vertebrate is a non-human mammal. In certainembodiments, the mammal is a non-human mammal. In certain embodiments,the vertebrate or mammal is an ovariectomized rat or an ovariectomizedmouse.

In certain embodiments, said determining comprises measuring a level ofbone mass in the vertebrate. In certain embodiments, said measuring alevel of bone mass comprises measuring the level of bone mass using DXA.In certain embodiments, said measuring a level of bone mass using DXAcomprises measuring a T-score using DXA. In certain embodiments, saidmeasuring a T-score using DXA comprises measuring a T-score at the hipusing DXA. It is expressly contemplated that said measuring a level ofbone mass may comprise measuring a level of bone mass using a techniqueother than DXA, such as single X-ray absorbtiometry (SXA) (see, e.g.,World Health Organization Technical Report Series 921 (2003), Preventionand Management of Osteoporosis). In certain embodiments, the vertebrateis a mammal. In certain embodiments, the vertebrate is a non-humanvertebrate. In certain embodiments, the vertebrate is a non-humanmammal. In certain embodiments, the mammal is a non-human mammal.

In certain embodiments, the human DNA sample is human genomic DNA.

In some embodiments, the polymerase chain reaction is reversetranscription-polymerase chain reaction (RT-PCR). RT-PCR techniques arewell known to the skilled artisan. In certain embodiments, the human DNAsample is human cDNA. In certain embodiments, the cDNA is from a humantissue that expresses GPR119. In some embodiments, the human tissue thatexpresses GPR119 is pancreas or pancreatic islet. In certainembodiments, the cDNA is from a human cell type that expresses GPR119.In some embodiments, the cDNA is from a pancreatic beta cell. In certainembodiments, the cDNA is from a pancreatic cell line.

In certain embodiments, the G protein-coupled receptor encoded by thepolynucleotide that is amplifiable by polymerase chain reaction is SEQID NO:2 or an allele thereof. In certain embodiments, the Gprotein-coupled receptor encoded by a polynucleotide that is amplifiableby polymerase chain reaction is an allele of SEQ ID NO:2. In certainembodiments, the G protein-coupled receptor encoded by a polynucleotidethat is amplifiable by polymerase chain reaction specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the G protein-coupled receptor encoded by apolynucleotide that is amplifiable by polymerase chain reaction is areceptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the G protein-coupled receptorencoded by a polynucleotide that is amplifiable by polymerase chainreaction exhibits a detectable level of constitutive activity. In someembodiments, the constitutive activity is for increasing a level ofintracellular cAMP. In some embodiments, the constitutive activity isfor causing melanophore cells to undergo pigment dispersion.

In certain embodiments, stringent hybridization conditions (e.g.,conditions of high stringency) comprise hybridization at 42° C. in asolution comprising 50% formamide, 5×SSC (1×SSC=150 mM NaCl, 15 mMtrisodium citrate), 50 mM sodium phosphate (pH 7.6), 5×Denhardt'ssolution, 10% dextran sulfate, and 20 μg/ml denatured, sheared salmonsperm DNA, followed by washing at 65° C. in a solution comprising0.1×SSC. Hybridization techniques are well known to the skilled artisan.

In certain embodiments, the GPCR encoded by a polynucleotide hybridizingunder conditions of high stringency to the complement of SEQ ID NO: 1 isSEQ ID NO:2 or an allele thereof. In certain embodiments, the GPCRencoded by a polynucleotide hybridizing under conditions of highstringency to the complement of SEQ ID NO: 1 is an allele of SEQ IDNO:2. In certain embodiments, the GPCR encoded by a polynucleotidehybridizing under conditions of high stringency to the complement of SEQID NO: 1 is an ortholog of SEQ ID NO:2. In certain embodiments, the GPCRencoded by a polynucleotide hybridizing under conditions of highstringency to the complement of SEQ ID NO: 1 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the GPCR encoded by a polynucleotide hybridizingunder conditions of high stringency to the complement of SEQ ID NO: 1 isa receptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the GPCR encoded by a polynucleotidehybridizing under conditions of high stringency to the complement of SEQID NO: 1 exhibits a detectable level of constitutive activity. In someembodiments, the constitutive activity is for increasing a level ofintracellular cAMP. In some embodiments, the constitutive activity isfor causing melanophore cells to undergo pigment dispersion.

In certain embodiments, the variant of SEQ ID NO: 2 is a GPCR. Incertain embodiments, the variant of SEQ ID NO: 2 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the variant of SEQ ID NO: 2 is a receptor forwhich(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist. In some embodiments, the variant of SEQ ID NO: 2 exhibitsa detectable level of constitutive activity. In some embodiments, theconstitutive activity is for increasing a level of intracellular cAMP.In some embodiments, the constitutive activity is for causingmelanophore cells to undergo pigment dispersion.

In some embodiments, the G protein-coupled receptor is part of a fusionprotein comprising a G protein. Techniques for making a GPCR:G fusionconstruct are well known to the skilled artisan (see, e.g.,International Application WO 02/42461).

In some embodiments, the compound in the presence of which less of acomplex between a G protein-coupled receptor and an optionally labelledknown ligand to the receptor is formed than in the absence of thecompound is a small molecule. In some embodiments, the compound in thepresence of which less of a complex between a G protein-coupled receptorand an optionally labelled known ligand to the receptor is formed thanin the absence of the compound is a small molecule, with the provisothat the small molecule is not a polypeptide. In some embodiments, thecompound in the presence of which less of a complex between a Gprotein-coupled receptor and an optionally labelled known ligand to thereceptor is formed than in the absence of the compound is a smallmolecule, with the proviso that the small molecule is not an antibody oran antigen-binding fragment thereof. In some embodiments, the compoundin the presence of which less of a complex between a G protein-coupledreceptor and an optionally labelled known ligand to the receptor isformed than in the absence of the compound is a small molecule, with theproviso that the small molecule is not a lipid. In some embodiments, thetest compound is a small molecule, with the proviso that the smallmolecule is not a polypeptide or a lipid. In some embodiments, the testcompound is a polypeptide. In some embodiments, the compound in thepresence of which less of a complex between a G protein-coupled receptorand an optionally labelled known ligand to the receptor is formed thanin the absence of the compound is a polypeptide, with the proviso thatthe polypeptide is not an antibody or an antigen-binding fragmentthereof. In some embodiments, the compound in the presence of which lessof a complex between a G protein-coupled receptor and an optionallylabelled known ligand to the receptor is formed than in the absence ofthe compound is a lipid. In some embodiments, the compound in thepresence of which less of a complex between a G protein-coupled receptorand an optionally labelled known ligand to the receptor is formed thanin the absence of the compound is not an antibody or an antigen-bindingfragment thereof. In some embodiments, the compound in the presence ofwhich less of a complex between a G protein-coupled receptor and anoptionally labelled known ligand to the receptor is formed than in theabsence of the compound is an antibody or an antigen-binding fragmentthereof.

In certain embodiments, the method is a method for identifying GIPsecretagogues.

In certain embodiments, the method is a method for identifying compoundsuseful for preventing or treating a condition characterized by low bonemass.

In certain embodiments, the method is a method for identifying compoundsuseful for increasing bone mass in an individual.

In certain embodiments, the known ligand is a ligand or agonist of anendogenous vertebrate, mammalian or human GPR119 receptor. In certainembodiments, the known ligand is a known agonist of an endogenousvertebrate, mammalian or human GPR119 receptor. In certain embodiments,the known ligand is a ligand or agonist of an endogenous human GPR119receptor. In certain embodiments, the known ligand is identical to acompound disclosed in, e.g., in International Application No.PCT/US2004/001267 (published as WO 04/065380); International ApplicationNo. PCT/US2004/005555 (published as WO 04/076413); InternationalApplication No. PCT/US2004/022327 (published as WO 05/007647);International Application No. PCT/US2004/022417 (published as WO05/007658); International Application No. PCT/US2005/019318 (publishedas WO 2005/121121); International Application No. PCT/GB2004/050046(published as WO 2005/061489); International Application No.PCT/US06/00567 (published as WO 2006/083491); International ApplicationNo. PCT/GB2005/050264 (published as WO 2006/067531); InternationalApplication No. PCT/GB2005/050265 (published as WO 2006/067532);International Application No. PCT/GB2005/050266 (published as WO2006/070208); International Application No. PCT/JP02/09350 (published asWO 03/026661); International Application No. PCT/JP2005/018412(published as WO 06/040966); International Application No.PCT/JP2005/019000 (published as WO 2006/043490); InternationalApplication No. PCT/GB2006/050176 (published as WO 2007/003960);International Application No. PCT/GB2006/050177 (published as WO2007/003961); International Application No. PCT/GB2006/050178 (publishedas WO 2007/003962); International Application No. PCT/GB2006/050182(published as WO 2007/003964); or International Application No.PCT/JP02/09350 (published as WO 03/026661). In certain embodiments, theknown ligand is(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the known ligand is an endogenous ligand of anendogenous vertebrate, mammalian, or human GPR119 receptor.

In certain embodiments, the optionally labeled known ligand is a labeledknown ligand. In certain embodiments, the labeled known ligand is aradiolabeled known ligand. Techniques for radiolabeling a compound, suchas for labeling a known ligand of a G protein-coupled receptor of theinvention, are well known to the skilled artisan. See, e.g.,International Application WO 04/065380. Also see, e.g., Example 11,infra.

Techniques for detecting the complex between a 0 protein-coupledreceptor and a compound known to be a ligand of the G protein-coupledreceptor are well known to the skilled artisan. See, e.g., InternationalApplication WO 04/065380. Also see, e.g., Example 12, infra.

In some embodiments, the method further comprises the step of optionallydetermining the structure of the GIP secretagogue, the compound usefulfor treating or preventing a condition characterized by low bone mass,or the compound useful for increasing bone mass in an individual.

In some embodiments, the method further comprises the step of optionallyproviding the name or structure of the GIP secretagogue, the compounduseful for treating or preventing a condition characterized by low bonemass, or the compound useful for increasing bone mass in an individual.

In some embodiments, said method further comprises the step ofoptionally producing or synthesizing the GIP secretagogue, the compounduseful for treating or preventing a condition characterized by low bonemass, or the compound useful for increasing bone mass in an individual.

In some embodiments, said method further comprises the step offormulating the GIP secretagogue, the compound useful for treating orpreventing a condition characterized by low bone mass, or the compounduseful for increasing bone mass in an individual as a pharmaceutical.

In some embodiments, said method further comprises the step offormulating the GIP secretagogue, the compound useful for treating orpreventing a condition characterized by low bone mass, or the compounduseful for increasing bone mass in an individual into a pharmaceuticalcomposition.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated in connection with the figures appendedhereto in which:

FIG. 1 shows a pharmacodynamic analysis of an effect of administrationof GPR119 agonist on blood GIP level in wild-type mice. A. A time courseanalysis carried out using Compound 1 as the GPR119 agonist. B. A timecourse analysis carried out using Compound 3 as the GPR119 agonist. C. Adose titration analysis carried out using Compound 3 as the GPR119agonist.

FIG. 2 shows an effect of administration of GPR119 agonist on blood GIPlevel in GPR119-deficient (knockout) mice compared to wild-type mice. A.The comparison was carried out using Compound 1 as the GPR119 agonist.B. The comparison was carried out using Compound 2 as the GPR119agonist.

DETAILED DESCRIPTION OF THE INVENTION

The present invention features methods of using GPR119 receptor toidentify compounds useful for increasing bone mass in an individual.Agonists of GPR119 receptor are useful as therapeutic agents fortreating or preventing a condition characterized by low bone mass, suchas osteoporosis, and for increasing bone mass in an individual. Thepresent invention is based, at least in part, on the surprisingdiscovery by Applicant that administration of a GPR119 agonist to anindividual, such as by oral administration, can act at GPR119 receptorto increase a GIP level in the individual.

The term “ligand”, as used herein, shall mean a molecule (e.g., testcompound) that specifically binds to a polypeptide, such as GPR119. Aligand may be, for example, a polypeptide, a lipid, a small molecule, anantibody. Compound 1 is an exemplary ligand of GPR119 receptorpolypeptide (see, Table A, which sets forth the chemical structure andchemical name of Compound 1). Compound 1 is identical to a compounddisclosed in International Patent Application No. PCT/US2004/001267(published as WO 2004/065380).(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine(see, Table A) is an exemplary ligand of GPR119 receptor polypeptide.Compound 2 is an exemplary ligand of GPR119 receptor polypeptide.Compound 2 is identical to a compound disclosed in International PatentApplication No. PCT/US2004/022417 (published as WO 2005/007658).Compound 3 is an exemplary ligand of GPR119 receptor polypeptide.Compound 3 is identical to a compound disclosed in International PatentApplication No. PCT/US2004/022327 (published as WO 2005/007647). Anendogenous ligand is a ligand that is an endogenous, natural ligand fora native polypeptide, such as GPR119. A ligand may be an “antagonist”,“agonist”, “partial agonist”, or “inverse agonist”, or the like.

TABLE A

(2-Fluoro-4-methanesulfonyl- phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol- 5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine

The term “agonist”, as used herein, shall mean an agent (e.g., ligand,test compound) that by virtue of binding to a GPCR activates the GPCR soas to elicit an intracellular response mediated by the GPCR.

The term “partial agonist”, as used herein, shall mean an agent (e.g.,ligand, test compound) that by virtue of binding to a GPCR activates theGPCR so as to elicit an intracellular response mediated by the GPCR,albeit to a lesser exent or degree than does a full agonist.

The term “antagonist” shall mean an agent (e.g., ligand, test compound)that binds, and preferably binds competitively, to a GPCR at about thesame site as an agonist or partial agonist but which does not activatean intracellular response initiated by the active form of the GPCR, andcan thereby inhibit the intracellular response by agonist or partialagonist. An antagonist typically does not diminish the baselineintracellular response in the absence of an agonist or partial agonist.

The term “inverse agonist” shall mean an agent (e.g., ligand, testcompound) which binds to a GPCR and which inhibits the baselineintracellular response initiated by the active form of the receptorbelow the normal base level activity which is observed in the absence ofan agonist or partial agonist.

The term “GPR119 agonist,” as used herein, refers to a compound thatbinds to GPR119 receptor and acts as an agonist. Compound 1 is anexemplary GPR119 agonist (see, Table A, which sets forth the chemicalstructure and chemical name of Compound 1). Compound 1 is identical to acompound disclosed in International Patent Application No.PCT/US2004/001267 (published as WO 2004/065380).(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an exemplary GPR119 agonist. Compound 2 is an exemplary GPR119agonist. Compound 2 is identical to a compound disclosed inInternational Patent Application No. PCT/US2004/022417 (published as WO2005/007658). Compound 3 is an exemplary GPR119 agonist. Compound 3 isidentical to a compound disclosed in International Patent ApplicationNo. PCT/US2004/022327 (published as WO 2005/007647).

The term “selective GPR119 agonist,” as used herein, refers to a GPR119agonist having selectivity for GPR119 receptor over one or more relatedreceptors, such as corticotrophin-releasing factor-1 (CRF-1) receptor.Compound 1 is an exemplary selective GPR119 agonist (see, Table A, whichsets forth the chemical structure and chemical name of Compound 1).Compound 1 is identical to a compound disclosed in International PatentApplication No. PCT/US2004/001267 (published as WO 2004/065380).(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an exemplary selective GPR119 agonist. Compound 2 is an exemplaryselective GPR119 agonist. Compound 2 is identical to a compounddisclosed in International Patent Application No. PCT/US2004/022417(published as WO 2005/007658). Compound 3 is an exemplary selectiveGPR119 agonist. Compound 3 is identical to a compound disclosed inInternational Patent Application No. PCT/US2004/022327 (published as WO2005/007647).

The term “GIP secretagogue” shall mean an agent (e.g., ligand, testcompound) that promotes secretion of GIP in a cell, e.g. anenteroendocrine cell, or that increases a level of total GIP, e.g. alevel of blood or plasma total GIP, on administration to an individualsuch as a vertebrate or a mammal. In certain embodiments, a GIPsecretagogue is a compound suitable for increasing a level of total GIPin an individual, for example a level of blood or plasma total GIP.

The term “individual,” as used herein, refers to a vertebrate, includingbut not limited to fish (such as commercially farmed fish, pet fish,etc.), amphibians (such as frogs, toads, pet amphibians, etc.), reptiles(such as snakes, lizards, turtles, pet reptiles, etc.), birds (such aschickens, turkeys, pet birds, etc.) and mammals (such as mice, rats,hamsters, rabbits, pigs, dogs, cats, horses, cows, sheep, goats,non-human primates, non-human mammals, pet non-human mammals, humans,etc.). In certain embodiments, the individual is a fish. In certainembodiments, the individual is an amphibian. In certain embodiments, theindividual is a reptile. In certain embodiments, the individual is abird. In certain embodiments, the individual is a turkey. Over the past25 yr, commercial selection pressure for turkeys with larger breastmuscle mass has placed increasing demands on skeletal integrity. Theincreased breast muscle mass, however, has not been accompanied bycompensatory changes in the skeleton, with the result that the turkeyindustry has experienced an increase in leg problems. Long bone fracturein young adult male turkeys has been reported. (See, e.g., Crespo et al,Poult Sci (2000) 79:602-608.) In certain embodiments, the individual isa mammal. In certain embodiments, the individual is a mouse, a rat, ahamster, a rabbit, a pig, a dog, a cat, a horse, a cow, a sheep, a goat,a non-human primate or a human (which may be included in embodiments ofthe invention individually or in any combination). In certainembodiments, the individual is a horse. Performance horses, which arehorses involved in activities such as racing, pacing and othercompetitive events, are susceptible to bone fracture. In certainembodiments, the individual is a dog or a cat. In certain embodiments,the individual is a human companion animal (such as a dog, a cat, etc.),a farm animal (such as a cow, a sheep, a goat, a pig, a chicken, etc.),a sports animal (such as a horse, a dog, etc.), a beast of burden (suchas a mule, a camel, etc.) or an exotic animal (such as an animal foundin a zoo, etc.), which may be included in embodiments of the inventionindividually or in any combination. In certain embodiments, theindividual is a non-human mammal. In certain embodiments, the individualis a non-human primate (such as a rhesus monkey, a chimpanzee, etc.). Incertain embodiments, the individual is a human.

The term “in need of prevention or treatment” as used herein refers to ajudgement made by a caregiver (e.g. physician, nurse, nurse practitionerin the case of humans; veterinarian in the case of non-humanvertebrates, and in particular embodiment non-human mammals) that anindividual requires or will benefit from treatment.

The term “therapeutically effective amount” or “therapeuticallyeffective dose” as used herein refers to the amount of active compoundor pharmaceutical agent that elicits the biological or medicinalresponse in a tissue, system, animal, individual or human that is beingsought by a researcher, veterinarian, medical doctor or other clinician,which includes one or more of the following:

(1) Preventing the disease; for example, preventing a disease, conditionor disorder in an individual that may be predisposed to the disease,condition or disorder but does not yet experience or display thepathology or symptomatology of the disease,(2) Inhibiting the disease; for example, inhibiting a disease, conditionor disorder in an individual that is experiencing or displaying thepathology or symptomatology of the disease, condition or disorder (i.e.,arresting further development of the pathology and/or symptomatology),and(3) Ameliorating the disease; for example, ameliorating a disease,condition or disorder in an individual that is experiencing ordisplaying the pathology or symptomatology of the disease, condition ordisorder (i.e., reversing the pathology and/or symptomatology).

The term “therapeutic efficacy” as used herein refers to elicitation ofthe biological or medicinal response in a tissue, system, animal,individual or human that is being sought by a researcher, veterinarian,medical doctor or other clinician, which includes one or more of thefollowing:

(1) Preventing the disease; for example, preventing a disease, conditionor disorder in an individual that may be predisposed to the disease,condition or disorder but does not yet experience or display thepathology or symptomatology of the disease,(2) Inhibiting the disease; for example, inhibiting a disease, conditionor disorder in an individual that is experiencing or displaying thepathology or symptomatology of the disease, condition or disorder (i.e.,arresting further development of the pathology and/or symptomatology),and(3) Ameliorating the disease; for example, ameliorating a disease,condition or disorder in an individual that is experiencing ordisplaying the pathology or symptomatology of the disease, condition ordisorder (i.e., reversing the pathology and/or symptomatology).

The term “amount that is effective to prevent” refers to that amount ofdrug that will prevent or reduce the risk of occurrence of thebiological or medical event that is sought to be prevented. In manyinstances, the amount that is effective to prevent is the same as thetherapeutically effective amount.

The term “composition” shall mean a material comprising at least onecomponent.

The term “active ingredient” shall mean any component that providespharmacological activity or other direct effect in the diagnosis, cure,mitigation, treatment, or prevention of disease.

The term “pharmaceutical composition” shall mean a compositioncomprising at least one active ingredient, whereby the composition isamenable to investigation and treatment in a mammal.

By “pharmaceutically acceptable” it is meant that the carrier, vehicle,diluent, excipients, and/or salt must be compatible with the otheringredients of the formulation, and not deleterious to the recipientthereof.

The term “dosage form” shall mean the physical form in which a drug isproduced and dispensed, such as a tablet, capsule, or an injectable.

By “bone” is intended the dense, semi-rigid, porous, calcifiedconnective tissue forming the major portion of the skeleton of mostvertebrates, comprising a dense organic matrix and an inorganic, mineralcomponent. Bone is any of numerous anatomically distinct structuresmaking up the skeleton of a vertebrate.

The terms “bone mass” and “bone mineral density (BMD)” are usedinterchangeably herein. BMD in humans is usually measured by a standardradiographic technique, dual energy X-ray absorptiometry (DXA). Of themany techniques developed to assess BMD, DXA is the most highlydeveloped technically and the most thoroughly validated biologically.DXA technology, with suitably adapted software, can also be used toreliably assess BMD in animal studies. DXA is used in the diagnosis ofosteoporosis, prognosis (fracture prediction), monitoring the naturalhistory of the disorder, and assessing response to treatment.

The term “low bone mass” as used herein refers to any decrease orreduction in bone mineral density (BMD) in an individual, and includesboth osteoporosis and osteopenia as defined in proposals by the WorldHealth Organization (WHO). The WHO has defined normal as a value of BMDwithin one standard deviation of the young adult reference mean (T-score≧−1). The WHO has defined osteopenia as a value of BMD more than 1standard deviation below the young adult mean, but less than 2.5standard deviations below this value (T-score <−1 and >−2.5). The WHOhas characterized osteoporosis as a more severe form of osteopenia, andhas defined it by value of BMD 2.5 standard deviations or more blow theyoung adult mean (T-score ≦−2.5). (See, e.g., World Health OrganizationTechnical Report Series 921 (2003), Prevention and Management ofOsteoporosis, the disclosure of which is herein incorporated byreference in its entirety.) More commonly, osteopenia is defined as aT-score of less than −1 and greater than −2, and osteoporosis is definedas a T-score of less than or equal to −2. In certain embodiments of thepresent invention, the T-score is measured at the hip with DXA.

The term “osteoporosis” as used herein is defined by a value of BMD 2standard deviations or more below the young adult reference mean(T-score ≦−2) or refers to a diagnosis made by a caregiver (e.g.physician, nurse, nurse practitioner in the case of humans; veterinarianin the case of non-human vertebrates).

Osteoporosis can be classified as either primary or secondary. (See,e.g., World Health Organization Technical Report Series 921 (2003),Prevention and Management of Osteoporosis.) As used herein, the term“osteoporosis” encompasses primary osteoporosis and secondaryosteoporosis. In certain embodiments, osteoporosis is primaryosteoporosis. In certain embodiments, osteoporosis is secondaryosteoporosis.

“Primary osteoporosis” as used herein is associated with menopause(natural, premature, or surgical), aging, or both. It shall beunderstood that in the present invention, primary osteoporosisassociated with menopause (natural, premature, or surgical), primaryosteoporosis associated with aging, and primary osteoporosis associatedwith menopause and aging can be included in embodiments individually orin any combination.

“Secondary osteoporosis” as used herein refers to osteoporosis which isassociated not with menopause or aging but rather with medicalconditions or with the use of medications or drugs. An increased risk ofosteoporosis is associated with a host of medical conditions, includingbut not limited to endocrine and metabolic disorders, and malignantdisease, and with the use of certain medications and drugs, examples ofwhich are well known to those skilled in the art (see, e.g., WorldHealth Organization Technical Report Series 921 (2003), Prevention andManagement of Osteoporosis; Williams Textbook of Endocrinology, 10^(th)Edition; the disclosure of which is herein incorporated by reference inits entirety.) Secondary osteoporosis can also be associated withimmobilization. A diagnosis of osteoporosis secondary to a medicalcondition, to use of a medication or drug, or to immobilization can bemade by a caregiver (e.g. physician, nurse, nurse practitioner in thecase of humans; veterinarian in the case of non-human vertebrates).

By “bone fracture” is intended a complete or incomplete break, ruptureor crack of a bone. Diagnosis of fractures normally depends uponclinical examination and radiological findings. In the invention, bonefractures include, but are not limited to, traumatic fractures,long-term fractures, and pathological fractures.

“Traumatic fracture” as used herein shall refer to an immediate fracturewhich involves a supraliminal trauma with a degree of local violencethat exceeds the natural elasticity of the bone. It can be accompaniedby simultaneous injury to the soft tissues and very often the skin. Atraumatic fracture can be closed (the adjacent soft tissue can beinjured but the covering soft parts are largely preserved). A traumaticfracture can be open (the broken ends of the bone are freed by extensivesoft tissue injury so that pathogens from outside can enter the wounddirectly).

“Long-term fracture” as used herein shall refer to a chronic fracture,fatigue fracture, stress fracture or spontaneous fracture type I.

“Pathological fracture” as used herein shall refer to a spontaneousfracture type II. A pathological fracture arises spontaneously, withoutadequate trauma to account for it. The bone may have been previouslydamaged, either by a systemic disease (e.g., osteoporosis,osteodystrophy, or Paget's osteitis deformans) or by a local bone lesion(e.g., metastasis, radioosteonecrosis, or bone tumor). See, Adler,Claus-Peter, BONE DISEASES, p. 114 (Springer-Verlag, Germany 2000).

Fractures also include, but are not limited no, oblique torsionfracture, transverse fracture, comminuted fracture, compressionfracture, rib fractures, creeping fracture, and fractured femoral neck(Adler, Claus-Peter, BONE DISEASES, Springer-Verlag, Germany (2000)).

As used herein, the term “condition characterized by low bone mass”includes but is not limited to osteopenia, osteoporosis, rheumatoidarthritis, osteoarthritis, periodontal disease, alveolar bone loss,osteotomy bone loss, childhood idiopathic bone loss, curvature of thespine and loss of height. In certain embodiments, osteoporosis isprimary osteoporosis. In certain embodiments, osteoporosis is secondaryosteoporosis. In certain embodiments, secondary osteoporosis isassociated with a medical condition. In certain embodiments, secondaryosteoporosis is associated with the use of a medication or drug. Incertain embodiments, secondary osteoporosis is associated withimmobilization. Conditions characterized by low bone mass also includebut are not limited to Paget's disease, bone loss due to metastaticcancer, and osteolytic lesions such as those caused by neoplasticdisease, radiotherapy, or chemotherapy. Conditions characterized by lowbone mass also include but are not limited to long-term complications ofosteoporosis such as curvature of the spine, loss of height andprosthetic surgery. It shall be understood that in the presentinvention, conditions characterized by low bone mass can be included inembodiments individually or in any combination. (See, e.g., World HealthOrganization Technical Report Series 921 (2003), Prevention andManagement of Osteoporosis; Williams Textbook of Endocrinology, 10^(th)Edition, Larsen et al, Eds. (2002), W.B. Saunders Company; andEndocrinology and Metabolism, 4^(th) Edition, Felig et al, Eds. (2001),McGraw-Hill Book Company; the disclosure of each of which is hereinincorporated by reference in its entirety.)

As used herein, “bone disease” refers to a disorder or conditionrelating to abnormality of the bone. Bone diseases that can be treatedaccording to the invention, by increasing bone mass or bone growth,include but are not limited to osteopenia, osteoporosis, rheumatoidarthritis, osteoarthritis, periodontal disease, alveolar bone loss,osteotomy bone loss, childhood idiopathic bone loss, curvature of thespine, and loss of height. In certain embodiments, osteoporosis isprimary osteoporosis. In certain embodiments, osteoporosis is secondaryosteoporosis. In certain embodiments, secondary osteoporosis isassociated with a medical conditions. In certain embodiments, secondaryosteoporosis is associated with the use of a medication or drug. Incertain embodiments, secondary osteoporosis is associated withimmobilization. Bone diseases that can be treated according to theinvention, by increasing bone mass or bone growth, also include but arenot limited to Paget's disease and bone loss due to metastatic cancer.Destructive bone disorders that can be treated according to theinvention, by increasing bone mass or growth, include but are notlimited to osteoporosis, osteoarthritis, and osteolytic lesions such asthose caused by neoplastic disease, radiotherapy, or chemotherapy. Itshall be understood that in the present invention, bone diseases thatcan be treated according to the invention, by increasing bone mass orgrowth, can be included in embodiments individually or in anycombination. (See, e.g., World Health Organization Technical ReportSeries 921 (2003), Prevention and Management of Osteoporosis; WilliamsTextbook of Endocrinology, 10^(th) Edition, Larsen et al, Eds. (2002),W.B. Saunders Company; and Endocrinology and Metabolism, 4^(th) Edition,Felig et al, Eds. (2001), McGraw-Hill Book Company; the disclosure ofeach of which is herein incorporated by reference in its entirety.)

The present invention also relates to the other conditions that derivebenefit from treatment according to the invention, by increasing bonemass or bone growth, including but not limited to enhanced bone healingfollowing facial reconstruction, maxillary reconstruction, mandibularreconstruction, periodontal disease or tooth extraction, enhanced longbone extension, enhanced prosthetic ingrowth and increased bonesynostosis.

The term “endogenous” shall mean a material that an individual (forexample, and not limitation, a human) naturally produces. By contrast,“non-endogenous” shall mean that which is not naturally produced by anindividual (for example, and not limitation, a human).

The term “biologically active fragment” of a 0 protein-coupled receptorshall mean a fragment of the GPCR having structural and biochemicalfunctions of a naturally occurring GPCR. In certain embodiments, thebiologically active fragment couples to a G protein. In certainembodiments, the biologically active fragment binds to a known ligand ofthe GPCR.

The term “primer” is used herein to denote a specific nucleotidesequence which is complementary to a target nucleotide sequence and usedto hybridize to the target nucleotide sequence. A primer servesas aninitiation point for nucleotide polymerization catalyzed by DNApolymerase, RNA polymerase, or reverse transcriptase.

The term “expression vector” shall mean a DNA sequence that is requiredfor the transcription of cloned DNA and translation of the transcribedmRNA in an appropriate host cell recombinant for the expression vector.An appropriately contructed expression vector should contain an originof replication for autonomous replication in host cells, selectablemarkers, a limited number of useful restriction enzyme sites, apotential for high copy number, and active promoters. The cloned DNA tobe transcribed is operably linked to a constitutively or conditionallyactive promoter within the expression vector.

The term “host cell” shall mean a cell capable of having a vectorincorporated therein. In the present context, the vector will typicallycontain nucleic acid encoding a GPCR or GPCR fusion protein in operableconnection with a suitable promoter sequence to permit expression of theGPCR or GPCR fusion protein to occur. In particular embodiment, the hostcell is a eukaryotic host cell. In certain embodiments, the eukaryotichost cell is a mammalian host cell. In certain embodiments, theeukaryotic host cell is a yeast host cell. In certain embodiments, theeukaryotic host cell is a melanophore host cell.

The term “contact” or “contacting” shall mean bringing at least twomoieties together. The terms “modulate” or “modify” shall be taken torefer to an increase or decrease in the amount, quality, or effect of aparticular activity, function or molecule. By way of illustration andnot limitation, agonists, partial agonists, inverse agonists, andantagonists of a G protein-coupled receptor are modulators of thereceptor.

The term “small molecule” shall be taken to mean a compound having amolecular weight of less than about 10,000 grams per mole, including apeptide, peptidomimetic, amino acid, amino acid analogue,polynucleotide, polynucleotide analogue, nucleotide, nucleotideanalogue, organic compound or inorganic compound (i.e. including aheterorganic compound or organometallic compound), and salts, esters andother pharmaceutically acceptable forms thereof. In certain embodiments,small molecules are organic or inorganic compounds having a molecularweight of less than about 5,000 grams per mole. In certain embodiments,small molecules are organic or inorganic compounds having molecularweight of less than about 1,000 grams per mole. In certain embodiments,small molecules are organic or inorganic compounds having a molecularweight of less than about 800 grams per mole. In certain embodiments,small molecules are organic or inorganic compounds having a molecularweight of less than about 600 grams per mole. In certain embodiments,small molecules are organic or inorganic compounds having a molecularweight of less than about 500 grams per mole.

Amino acid abbreviations used herein are set out in Table B:

TABLE B ALANINE ALA A ARGININE ARG R ASPARAGINE ASN N ASPARTIC ACID ASPD CYSTEINE CYS C GLUTAMIC ACID GLU E GLUTAMINE GLN Q GLYCINE GLY GHISTIDINE HIS H ISOLEUCINE ILE I LEUCINE LEU L LYSINE LYS K METHIONINEMET M PHENYLALANINE PHE F PROLINE PRO P SERINE SER S THREONINE THR TTRYPTOPHAN TRP W TYROSINE TYR Y VALINE VAL V

The term “polypeptide” shall refer to a polymer of amino acids withoutregard to the length of the polymer. Thus, peptides, oligopeptides, andproteins are included within the definition of polypeptide. This termalso does not specify or exclude post-expression modifications ofpolypeptides. For example, polypeptides that include the covalentattachment of glycosyl groups, acetyl groups, phosphate groups, lipidgroups and the like are expressly encompassed by the term polypeptide.

The term “polynucleotide” shall refer to RNA, DNA, or RNA/DNA hybridsequence of more than one nucleotide in either single chain or duplexform. The polynucleotides of the invention may be prepared by any knownmethod, including synthetic, recombinant, ex vivo generation, or acombination thereof, as well as utilizing any purification methods knownin the art.

The term “antibody” is intended herein to encompass monoclonal antibodyand polyclonal antibody.

The term “second messenger” shall mean an intracellular responseproduced as a result of receptor activation. A second messenger caninclude, for example, inositol 1,4,5-triphosphate (IP₃), diacylglycerol(DAG), cyclic AMP (cAMP), cyclic GMP (cGMP), MAP kinase activity,MAPK/ERK kinase kinase-1 (MEKK1) activity, and Ca²⁺. Second messengerresponse can be measured for a determination of receptor activation.

The term “receptor functionality” shall refer to the normal operation ofa receptor to receive a stimulus and moderate an effect in the cell,including, but not limited to regulating gene transcription, regulatingthe influx or efflux of ions, effecting a catalytic reaction, and/ormodulating activity through G-proteins, such as eliciting a secondmessenger response.

The term “stimulate” or “stimulating,” in relationship to the term“response” or “functionality of the receptor” shall mean that a responseor a functionality of the receptor is increased in the presence of acompound as opposed to in the absence of the compound.

The term “inhibit” or “inhibiting,” in relationship to the term“response” or “functionality of the receptor” shall mean that a responsea functionality of the receptor is decreased or prevented in thepresence of a compound as opposed to in the absence of the compound.

The term “compound efficacy” shall mean a measurement of the ability ofa compound to inhibit or stimulate receptor functionality, as opposed toreceptor binding affinity.

The term “test compound,” used interchangeably herein with “candidatecompound,” shall mean a molecule (for example, and not limitation, achemical compound) which is amenable to a screening technique.

The term “constitutively active” in relationship to a G protein-coupledreceptor shall mean that the G protein-coupled receptor exhibitsagonist-independent activity.

The term “directly identifying” or “directly identified”, inrelationship to the phrase “test compound,” shall mean the screening ofa compound against a G protein-coupled receptor in the absence of aknown ligand (e.g., a known agonist) to the G protein-coupled receptor.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the lower limit unless the contextclearly indicates otherwise, between the upper and lower limit of thatrange and any other stated or intervening value in that stated range, isencompassed within the invention. The upper and lower limits of thesesmaller ranges may independently be included in the smaller ranges, andare also encompassed within the invention, subject to any specificallyexcluded limit in the stated range. Where the stated range includes oneor both of the limits, ranges excluding either or both of those includedlimits are also included in the invention.

A. Introduction

The order of the following sections is set forth for presentationalefficiency and is not intended, nor should be construed, as a limitationon the disclosure or the claims to follow.

B. Receptor Expression

1. GPCR Polypeptides of Interest

A GPCR of the invention may comprise an amino acid sequence selectedfrom the group consisting of:

-   -   (a) amino acids 1-335 of SEQ ID NO: 2;    -   (b) amino acids 2-335 of SEQ ID NO: 2;    -   (c) amino acids 2-335 of SEQ ID NO: 2, wherein the GPCR does not        comprise the amino acid sequence of SEQ ID NO: 2;    -   (d) the amino acid sequence of a G protein-coupled receptor        encoded by a polynucleotide that is amplifiable by polymerase        chain reaction (PCR) on a human DNA sample using specific        primers SEQ ID NO: 3 and SEQ ID NO: 4;    -   (e) the amino acid sequence of a G protein-coupled receptor        encoded by a polynucleotide hybridizing under conditions of high        stringency to the complement of SEQ ID NO: 1;    -   (f) a variant of SEQ ID NO: 2;    -   (g) the amino acid sequence of (f) when selected from the group        consisting of:        -   (i) the amino acid sequence of a G protein-coupled receptor            having at least about 80% identity to SEQ ID NO: 2; and        -   (ii) the amino acid sequence of a G protein-coupled receptor            comprising at least 20 contiguous amino acids of SEQ ID NO:            2;    -   (h) the amino acid sequence of a constitutively active version        of a G protein-coupled receptor having SEQ ID NO: 2; and    -   (i) a biologically active fragment of any one of any one of (a)        to (h).        In certain embodiments, a GPCR of the invention comprises the        amino acid sequence of SEQ ID NO: 2.

In some embodiments, the G protein-coupled receptor encoded by thepolynucleotide that is amplifiable by polymerase chain reaction is anendogenous G protein-coupled receptor. In some embodiments, the Gprotein-coupled receptor encoded by the polynucleotide that isamplifiable by polymerase chain reaction and that is an endogenous Gprotein-coupled receptor is a mammalian G protein-coupled receptor. Insome embodiments, the G protein-coupled receptor encoded by thepolynucleotide that is amplifiable by polymerase chain reaction and thatis an endogenous G protein-coupled receptor is a mammalian GPR119receptor. In certain embodiments, the G protein-coupled receptor encodedby the polynucleotide that is amplifiable by polymerase chain reactionis SEQ ID NO:2 or an allele thereof. In certain embodiments, the Gprotein-coupled receptor encoded by a polynucleotide that is amplifiableby polymerase chain reaction is an allele of SEQ ID NO:2. In certainembodiments, the G protein-coupled receptor encoded by thepolynucleotide that is amplifiable by polymerase chain reactionspecifically binds Compound 1 (see Table A, which sets forth thechemical structure and chemical name of Compound 1). In certainembodiments, the G protein-coupled receptor encoded by thepolynucleotide that is amplifiable by polymerase chain reactionspecifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the G protein-coupled receptor encoded by thepolynucleotide that is amplifiable by polymerase chain reactionspecifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-aminewith an IC₅₀ value in receptor binding assay according to Example 12,infra, of less than about 50 μM, less than about 25 μM, less than about10 μM, less than about 5 μM, less than about 1 μM, less than about 500nM, less than about 100 nM, or less than about 50 nM. In certainembodiments, the G protein-coupled receptor encoded by thepolynucleotide that is amplifiable by polymerase chain reactionspecifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-aminewith an IC₅₀ value in receptor binding assay according to Example 12,infra, of less than about 10 μM, less than about 5 μM, less than about 1μM, less than about 500 nM, less than about 100 nM, or less than about50 nM. In certain embodiments, the G protein-coupled receptor encoded bythe polynucleotide that is amplifiable by polymerase chain reaction is areceptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist having an EC₅₀ value at said receptor in whole celladenylyl cyclase assay according to Example 8, infra, of less than about5 μM, less than about less than about 100 nM, less than about 50 nM,less than about 25 nM, less than about 10 nM, less than about 5 nM, orless than about 1 nM. In certain embodiments, the G protein-coupledreceptor encoded by the polynucleotide that is amplifiable by polymerasechain reaction is a receptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist having an EC₅₀ value at said receptor in whole celladenylyl cyclase assay according to Example 8, infra, of less than about100 nM, less than about 50 nM, less than about 25 nM, less than about 10nM, less than about 5 nM, or less than about 1 nM. In some embodiments,the G protein-coupled receptor encoded by the polynucleotide that isamplifiable by polymerase chain reaction exhibits a detectable level ofconstitutive activity. In some embodiments, the constitutive activity isfor increasing a level of intracellular cAMP. In some embodiments, theconstitutive activity is for causing melanophore cells to undergopigment dispersion.

In some embodiments, the human DNA is genomic DNA.

In some embodiments, the polymerase chain reaction is reversetranscription-polymerase chain reaction (RT-PCR). RT-PCR techniques arewell known to the skilled artisan. In some embodiments, the human DNA ishuman cDNA derived from a tissue or cell type that expresses GPR119. Insome embodiments, the human tissue that expresses GPR119 is pancreas orpancreatic islet. In certain embodiments, the cDNA is from a human celltype that expresses GPR119. In some embodiments, the cDNA is from apancreatic beta cell line.

In some embodiments, a GPCR of the invention is recombinant. In someembodiments, the recombinant GPCR is recombinant human GPR119.

In certain embodiments, a GPCR that may be used in the subject methodsexhibits a detectable level of constitutive activity.

In some embodiments, a GPCR of the invention is endogenous. In someembodiments, a GPCR of the invention is a mammalian GPR119. In someembodiments, a GPCR of the invention that is endogenous is a mammalianGPR119.

By way of illustration and not limitation, deletion of an N-terminalmethionine residue is envisioned to provide a biologically activefragment that may be used in the subject invention. In certainembodiments, a biologically active fragment of the invention is afragment optionally fused at its N-terminus to a peptide comprising anN-terminal methionine residue and an HA epitope tag (from hemagglutinininfluenza virus) that specifically binds Compound 1. In certainembodiments, a biologically active fragment of the invention is afragment optionally fused at its N-terminus to a peptide comprising anN-terminal methionine residue and an HA epitope tag (from hemagglutinininfluenza virus) that specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, a biologically active fragment of the inventionis a fragment optionally fused at its N-terminus to a peptide comprisingan N-terminal methionine residue and an HA epitope tag that specificallybinds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-aminewith an IC₅₀ value in receptor binding assay according to Example 12,infra, of less than about 50 μM, less than about 25 μM, less than about10 μM, less than about 5 μM, less than about 1 μM, less than about 500nM, less than about 100 nM, or less than about 50 nM. In certainembodiments, a biologically active fragment of the invention is afragment optionally fused at its N-terminus to a peptide comprising anN-terminal methionine residue and an HA epitope tag that specificallybinds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-aminewith an IC₅₀ value in receptor binding assay according to Example 12,infra, of less than about 10 μM, less than about 5 μM, less than about 1μM, less than about 500 nM, less than about 100 nM, or less than about50 nM. In certain embodiments, a biologically active fragment of theinvention is a fragment optionally fused at its N-terminus to a peptidecomprising an N-terminal methionine residue and an HA epitope tag forwhich(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist having an EC₅₀ value at said fragment optionally fused atits N-terminus to said peptide in whole cell adenylyl cyclase assayaccording to Example 8, infra, of less than about 5 μM, less than about1 μM, less than about 100 nM, less than about 50 nM, less than about 25nM, less than about 10 nM, less than about 5 nM, or less than about 1nM. In certain embodiments, a biologically active fragment of theinvention is a fragment optionally fused at its N-terminus to a peptidecomprising an N-terminal methionine residue and an HA epitope tag forwhich(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist having an EC₅₀ value at said fragment optionally fused atits N-terminus to said peptide in whole cell adenylyl cyclase assayaccording to Example 8, infra, of less than about 100 nM, less thanabout 50 nM, less than about 25 nM, less than about 10 nM, less thanabout 5 nM, or less than about 1 nM. In some embodiments, a biologicallyactive fragment of the invention is a fragment optionally fused at itsN-terminus to a peptide comprising an N-terminal methionine residue andan HA epitope tag that exhibits a detectable level of constitutiveactivity. In some embodiments, the constitutive activity is forincreasing a level of intracellular cAMP. In some embodiments, theconstitutive activity is for causing melanophore cells to undergopigment dispersion. In certain embodiments, the fragment is fused at itsN-terminus to a peptide consisting essentially of an N-terminalmethionine residue and an HA epitope tag. Techniques for fusing apeptide comprising or consisting essentially of an N-terminal methionineresidue and an HA epitope tag to the N-terminus of a polypeptidefragment are well known in the art and can be obtained commercially(e.g., Clontech, Mountain View, Calif.).

An allelic variant of human GPR119 of SEQ ID NO: 2 is envisioned to bewithin the scope of the invention. Human GPR119 is envisioned to bewithin the scope of the invention.

A variant which is a vertebrate ortholog of human GPR119 of SEQ ID NO: 2is envisioned to be within the scope of the invention. A variant whichis a mammalian ortholog of human GPR119 of SEQ ID NO: 2 is envisioned tobe within the scope of the invention. By way of illustration and notlimitation, mouse GPR119 (e.g., GenBank® Accession No. AY288423), ratGAR (GenBank® Accession No. AAN95195), hamster GPR119, dog GPR119, andnon-human primate GPR119 are envisioned to be within the scope of theinvention.

In certain embodiments, the variant of SEQ ID NO: 2 is a GPCR.

A variant of SEQ ID NO: 2 having at least about 80%, at least about 85%,at least about 90%, at least about 95%, at least about 96%, at leastabout 97%, at least about 98%, or at least about 99% identity to SEQ IDNO: 2 is envisioned to be within the scope of the invention. In certainembodiments, the variant of SEQ ID NO: 2 having at least about 80%, atleast about 85%, at least about 90%, at least about 95%, at least about96%, at least about 97%, at least about 98%, or at least about 99%identity to SEQ ID NO: 2 is a GPCR. In some embodiments, the variant ofSEQ ID NO: 2 is an endogenous GPCR. In some embodiments, the variant ofSEQ ID NO: 2 is a non-endogenous GPCR. In some embodiments, the variantof SEQ ID NO: 2 that is an endogenous GPCR is a mammalian GPCR. Incertain embodiments, the variant of SEQ ID NO: 2 specifically bindsCompound 1. In certain embodiments, the variant of SEQ ID NO: 2specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the variant of SEQ ID NO: 2 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-aminewith an IC₅₀ value in receptor binding assay according to Example 12,infra, of less than about 50 μM, less than about 25 μM, less than about10 μM, less than about 5 μM, less than about 1 μM, less than about 500nM, less than about 100 nM, or less than about 50 nM. In certainembodiments, the variant of SEQ ID NO: 2 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-(1,2,4]oxadiazol-5-yl)-piperidin-1-yl)-5-nitro-pyrimidin-4-yl}-aminewith an IC₅₀ value in receptor binding assay according to Example 12,infra, of less than about 10 μM, less than about 5 μM, less than about 1μM, less than about 500 nM, less than about 100 nM, or less than about50 nM. In certain embodiments, the variant of SEQ ID NO: 2 is a receptorfor which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist having an EC₅₀ value at said receptor in whole celladenylyl cyclase assay according to Example 8, infra, of less than about5 μM, less than about 1 μM, less than about 100 nM, less than about 50nM, less than about 25 nM, less than about 10 nM, less than about 5 nM,or less than about 1 nM. In certain embodiments, the variant of SEQ IDNO: 2 is a receptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist having an EC₅₀ value at said receptor in whole celladenylyl cyclase assay according to Example 8, infra, of less than about100 nM, less than about 50 nM, less than about 25 nM, less than about 10nM, less than about 5 nM, or less than about 1 nM. In some embodiments,the variant of SEQ ID NO: 2 exhibits a detectable level of constitutiveactivity. In some embodiments, the constitutive activity is forincreasing a level of intracellular cAMP. In some embodiments, theconstitutive activity is for causing melanophore cells to undergopigment dispersion. Percent identity can be determined conventionallyusing known computer programs.

In certain embodiments, a variant GPCR that may be used in the subjectmethods has an amino acid sequence having at least about 80%, at leastabout 85%, at least about 90%, at least about 95%, of at least about96%, at least about 97%, at least about 98%, or at least about 99%identity to SEQ ID NO: 2. By a variant GPCR having, for example, 95%“identity” to SEQ ID NO: 2 is meant that the amino acid sequence of thevariant is identical to amino acids 1-335 of SEQ ID NO: 2 except that itmay include up to five amino acid alterations per each 100 amino acidsof SEQ ID NO: 2. Thus, to obtain for example an amino acid sequencehaving at least 95% identity to the amino acid sequence of SEQ ID NO: 2,up to 5% (5 of 100) of the amino acid residues in the sequence may beinserted, deleted, or substituted with another amino acid compared withamino acids 1-335 of SEQ ID NO: 2. These alternations may occur at theamino or carboxy termini or anywhere between those terminal positions,interspersed either subjectly among residues in the sequence or in oneor more contiguous groups within the sequence.

In certain embodiments, a variant G protein-coupled receptor that may beused in the subject methods is a G protein-coupled receptor having anamino acid sequence derived from SEQ ID NO: 2 by deletion, substitution,and/or addition of one or several amino acids. In certain embodiments, avariant G protein-coupled receptor that may be used in the subjectmethods is a G protein-coupled receptor having an amino acid sequencederived from SEQ ID NO: 2 by no more than 10 conservative amino acidsubstitutions and/or no more than 3 non-conservative amino acidsubstitutions in the amino acid sequence of SEQ ID NO: 2. In certainembodiments, arginine, lysine and histidine may conservativelysubstitute for each other; glutamic acid and aspartic acid mayconservatively substitute for each other; glutamine and asparagine mayconservatively substitute for each other; leucine, isoleucine and valinemay conservatively substitute for each other; phenylalanine, tryptophanand tyrosine may conservatively substitute for each other; and glycine,alanine, serine, threonine and methionine may conservatively substitutefor each other. The amino acid substitutions, amino acid deletions, andamino acid additions may be at any position (e.g., the C- or N-terminus,or at internal positions). In some embodiments, the variant is anendogenous G protein-coupled receptor. In some embodiments, the variantis an endogenous vertebrate G protein-coupled receptor. In someembodiments, the variant is an endogenous mammalian G protein-coupledreceptor. In some embodiments, the variant is an endogenous human Gprotein-coupled receptor. In some embodiments, the variant is anon-endogenous G protein-coupled receptor. In some embodiments, thevariant exhibits a detectable level of constitutive activity. In someembodiments, the constitutive activity is for increasing intracellularcAMP. In some embodiments, the constitutive activity is for causingmelanophore cells to undergo pigment dispersion. In certain embodiments,said G protein-coupled receptor having an amino acid sequence derivedfrom SEQ ID NO: 2 is a G protein-coupled receptor for which Compound 1is a ligand. In certain embodiments, said G protein-coupled receptorhaving an amino acid sequence derived from SEQ ID NO: 2 is a Gprotein-coupled receptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis a ligand having an IC₅₀ value in receptor binding assay according toExample 12, infra, of less than about 50 μM, less than about 25 μM, lessthan about 10 μM, less than about 5 μM, less than about 1 μM, less thanabout 500 nM, less than about 100 nM, or less than about 50 nM. Incertain embodiments, said G protein-coupled receptor having an aminoacid sequence derived from SEQ ID NO: 2 is a G protein-coupled receptorfor which Compound 1 is an agonist. In certain embodiments, said Gprotein-coupled receptor having an amino acid sequence derived from SEQID NO: 2 is a G protein-coupled receptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist having an EC₅₀ value in whole cell adenylyl cyclase assayaccording to Example 8, infra, of less than about 5 μM, less than about1 μM, less than about 100 nM, less than about 50 nM, less than about 25nM, less than about 10 nM, less than about 5 nM, or less than about 1nM.

A variant of SEQ ID NO: 2 that is a G protein-coupled receptorcomprising at least 20, at least 30, at least 40, at least 50, at least75, or at least 100 contiguous amino acids of SEQ ID NO: 2 is envisionedto be within the scope of the invention. In certain embodiments, thevariant of SEQ ID NO: 2 comprising at least 20, at least 30, at least40, at least 50, at least 75, or at least 100 contiguous amino acids ofSEQ ID NO: 2 is a GPCR. In some embodiments, the variant of SEQ ID NO: 2is an endogenous GPCR. In some embodiments, the variant of SEQ ID NO: 2is a non-endogenous GPCR. In some embodiments, the variant of SEQ ID NO:2 that is an endogenous GPCR is a mammalian GPCR. In certainembodiments, the variant of SEQ ID NO: 2 specifically binds Compound 1.In certain embodiments, the variant of SEQ ID NO: 2 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the variant of SEQ ID NO: 2 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-aminewith an IC₅₀ value in receptor binding assay according to Example 12,infra, of less than about 50 μM, less than about 25 μM, less than about10 μM, less than about 5 μM, less than about 1 μM, less than about 500nM, less than about 100 nM, or less than about 50 nM. In certainembodiments, the variant of SEQ ID NO: 2 specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-aminewith an IC₅₀ value in receptor binding assay according to Example 12,infra, of less than about 10 μM, less than about 5 μM, less than about 1μM, less than about 500 nM, less than about 100 nM, or less than about50 nM. In certain embodiments, the variant of SEQ ID NO: 2 is a receptorfor which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist having an EC₅₀ value at said receptor in whole celladenylyl cyclase assay according to Example 8, infra, of less than about5 μM, less than about 1 μM, less than about 100 nM, less than about 50nM, less than about 25 nM, less than about 10 nM, less than about 5 nM,or less than about 1 nM. In certain embodiments, the variant of SEQ IDNO: 2 is a receptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist having an EC₅₀ value at said receptor in whole celladenylyl cyclase assay according to Example 8, infra, of less than about100 nM, less than about 50 nM, less than about 25 nM, less than about 10nM, less than about 5 nM, or less than about 1 nM. In some embodiments,the variant of SEQ ID NO: 2 exhibits a detectable level of constitutiveactivity. In some embodiments, the constitutive activity is forincreasing a level of intracellular cAMP. In some embodiments, theconstitutive activity is for causing melanophore cells to undergopigment dispersion. In some embodiments, the G protein-coupled receptorcomprising at least 20, at least 30, at least 40, at least 50, at least75, or at least 100 contiguous amino acids of SEQ ID NO: 2 exhibits adetectable level of constitutive activity. In some embodiments, theconstitutive activity is for increasing a level of intracellular cAMP.In some embodiments, the constitutive activity is for causingmelanophore cells to undergo pigment dispersion.

In some embodiments, a variant GPCR that may be used in the subjectmethods is a GPCR encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO: 1. In someembodiments, the GPCR encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO: 1 is anendogenous GPCR. In some embodiments, the GPCR encoded by apolynucleotide hybridizing under conditions of high stringency to thecomplement of SEQ ID NO: 1 is a non-endogenous GPCR. In someembodiments, the GPCR encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO: 1 and thatis an endogenous GPCR is a mammalian endogenous GPCR. In certainembodiments, the GPCR encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO: 1 is SEQID NO:2 or an allele thereof. In certain embodiments, the GPCR encodedby a polynucleotide hybridizing under conditions of high stringency tothe complement of SEQ ID NO: 1 is an allele of SEQ ID NO:2. In certainembodiments, the GPCR encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO: 1 is anortholog of SEQ ID NO:2. In certain embodiments, the GPCR encoded by apolynucleotide hybridizing under conditions of high stringency to thecomplement of SEQ ID NO: 1 specifically binds Compound 1. In certainembodiments, the GPCR encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO: 1specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine.In certain embodiments, the GPCR encoded by a polynucleotide hybridizingunder conditions of high stringency to the complement of SEQ ID NO: 1specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-aminewith an IC₅₀ value in receptor binding assay according to Example 12,infra, of less than about 50 μM, less than about 25 μM, less than about10 μM, less than about 5 μM, less than about 1 μM, less than about 500nM, less than about 100 nM, or less than about 50 nM. In certainembodiments, the GPCR encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO: 1specifically binds(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-aminewith an IC₅₀ value in receptor binding assay according to Example 12,infra, of less than about 10 μM, less than about 5 μM, less than about 1μM, less than about 500 nM, less than about 100 nM, or less than about50 nM. In certain embodiments, the GPCR encoded by a polynucleotidehybridizing under conditions of high stringency to the complement of SEQID NO: 1 is a receptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist having an EC₅₀ value at said receptor in whole celladenylyl cyclase assay according to Example 8, infra, of less than about5 μM, less than about 1 μM, less than about 100 nM, less than about 50nM, less than about 25 nM, less than about 10 nM, less than about 5 nM,or less than about 1 nM. In certain embodiments, the GPCR encoded by apolynucleotide hybridizing under conditions of high stringency to thecomplement of SEQ ID NO: 1 is a receptor for which(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amineis an agonist having an EC₅₀ value at said receptor in whole celladenylyl cyclase assay according to Example 8, infra, of less than about100 nM, less than about 50 nM, less than about 25 nM, less than about 10nM, less than about 5 nM, or less than about 1 nM. In some embodiments,the GPCR encoded by a polynucleotide hybridizing under conditions ofhigh stringency to the complement of SEQ ID NO: 1 exhibits a detectablelevel of constitutive activity. In some embodiments, the constitutiveactivity is for increasing a level of intracellular cAMP. In someembodiments, the constitutive activity is for causing melanophore cellsto undergo pigment dispersion. Hybridization techniques are well knownto the skilled artisan. In some embodiments, stringent hybridizationconditions (e.g., conditions of high stringency) include overnightincubation at 42° C. in a solution comprising: 50% formamide, 5×SSC(1×SSC=150 mM NaCl, 15 mM trisodium citrate), 50 mM sodium phosphate (pH7.6), 5×Denhardt's solution, 10% dextran sulfate, and 20 μg/mldenatured, sheared salmon sperm DNA; followed by washing the filter in0.1×SSC at about 65° C. In some embodiments, stringent hybridizationconditions (e.g., conditions of high stringency) include overnightincubation at 42° C. in a solution comprising: 50% formamide, 5×SSC(1×SSC=150 mM NaCl, 15 mM trisodium citrate), 50 mM sodium phosphate (pH7.6), 5×Denhardt's solution, 10% dextran sulfate, and 20 μg/mldenatured, sheared salmon sperm DNA; followed by a wash in 0.1×SSC/0.1%SDS (sodium dodecyl sulfate) or in 0.2×SSC/0.1% SDS at about 50° C., atabout 55° C., at about 60° C. or at about 65° C. In some embodiments,said conditions of high stringency comprise washing at 65° C. with0.1×SSC. In some embodiments, said conditions of high stringencycomprise washing at about 50° C., at about 55° C., at about 60° C., orat about 65° with 0.1×SSC/0.1% SDS or with 0.2×SSC/0.1% SDS.

In some embodiments, a GPCR that may be used in the subject methods is anon-endogenous, constitutively activated receptor comprising the aminoacid sequence of SEQ ID NO: 2, wherein the leucine at amino acidposition 224 of SEQ ID NO: 2 is substituted with an amino acid otherthan leucine. In some embodiments, the amino acid other than leucine islysine. In some embodiments, the amino acid other than leucine isalanine. In some embodiments, the amino acid other than leucine isarginine. In some embodiments, the amino acid other than leucine ishistidine. In some embodiments, the constitutive activity is forincreasing a level of intracellular cAMP. In some embodiments, theconstitutive activity is for causing melanophore cells to undergopigment dispersion.

In certain embodiments, a GPCR of the invention comprises aconstitutively active version of a G protein-coupled receptor having SEQID NO: 2. In some embodiments, the constitutively active version of thereceptor is an endogenous constitutively active version having SEQ IDNO: 2. In some embodiments, the constitutively active version of thereceptor is a non-endogenous constitutively active version having amutation positioned at amino acid position 224 of SEQ ID NO: 2. In someembodiments, the mutated residue has been mutated to a residue otherthan leucine. In some embodiments, the mutated residue has been mutatedto a lysine residue. In some embodiments, the mutated residue has beenmutated to an alanine residue. In some embodiments, the mutated residuehas been mutated to an arginine residue. In some embodiments, themutated residue has been mutated to a histidine residue. In someembodiments, the constitutive activity is for increasing a level ofintracellular cAMP. In some embodiments, the constitutive activity isfor causing melanophore cells to undergo pigment dispersion.

In certain embodiments, a GPCR of the invention forms part of a fusionprotein with a G protein.

a. Sequence Identity

In certain embodiments, percent identity is evaluated using the BasicLocal Alignment Search Tool (“BLAST”), which is well known in the art[See, e.g., Karlin and Altschul, Proc Natl Acad Sci USA (1990)87:2264-2268; Altschul et al., J Mol Biol (1990) 215:403-410; Altschulet all, Nature Genetics (1993) 3:266-272; and Altschul et al., NucleicAcids Res (1997) 25:3389-3402; the disclosure of each of which is hereinincorporated by reference in its entirety]. The BLAST programs may beused with the default parameters or with modified parameters provided bythe user. Preferably, the parameters are default parameters.

In certain embodiments, a preferred method for determining the bestoverall match between a query sequence (e.g., the amino acid sequence ofSEQ ID NO:2) and a sequence to be interrogated, also referred to as aglobal sequence alignment, can be determined using the FASTDB computerprogram based on the algorithm of Brutlag et al. (Comp App Biosci (1990)6:237-245; the disclosure of which is herein incorporated by referencein its entirety). In a sequence alignment the query and interrogatedsequences are both amino acid sequences. The results of said globalsequence alignment is in percent identity. Preferred parameters used ina FASTDB amino acid alignment are: Matrix=PAM 0, k-tuple=2, MismatchPenalty=1, Joining Penalty=20, Randomization Group=25, Length=0, CutoffScore=1, Window Size=sequence length, Gap Penalty=5, Gap SizePenalty=0.05, Window Size=247 or the length of the interrogated aminoacid sequence, whichever is shorter. If the interrogated sequence isshorter than the query sequence due to N- or C-terminal deletions, notbecause of internal deletions, the results, in percent identity, must bemanually corrected because the FASTDB program does not account for N-and C-terminal truncations of the interrogated sequence when calculatingglobal percent identity. For interrogated sequences truncated at the N-and C-termini, relative to the query sequence, the percent identity iscorrected by calculating the number of residues of the query sequencethat are N- and C-terminal of the interrogated sequence, that are notmatched/aligned with a corresponding interrogated sequence residue, as apercent of the total bses of the query sequence. Whether a residue ismatched/aligned is determined by results of the FASTDB sequencealignment. This percentage is then subtracted from the percent identity,calculated by the above FASTDB program using the specified parameters,to arrive at a final percent identity score. This final percent identityscore is what is used for the purposes of the present invention. Onlyresidues to the N- and C-termini of the interrogated sequence, which arenot matched/aligned with the query sequence, are considered for thepurposes of manually adjusting the percent identity score. That is, onlyquery amino acid residues outside the farthest N- and C-terminalresidues of the interrogated sequence.

For example, a 90 amino acid residue interrogated sequence is alignedwith a 100-residue query sequence to determine percent identity. Thedeletion occurs at the N-terminus of the interrogated sequence andtherefore, the FASTDB alignment does not match/align with the firstresidues at the N-terminus. The 10 unpaired residues represent 10% ofthe sequence (number of residues at the N- and C-termini notmatched/total number of residues in the query sequence) so 10% issubtracted from the percent identity score calculated by the FASTDBprogram. If the remaining 90 residues were perfectly matched, the finalpercent identity would be 90%.

In another example, a 90-residue interrogated sequence is compared witha 100-residue query sequence. This time the deletions are internal sothere are no residues at the N- or C-termini of the interrogatedsequence, which are not matched/aligned with the query. In this case,the percent identity calculated by FASTDB is not manually corrected.Once again, only residue positions outside the N- and C-terminal ends ofthe subject sequence, as displayed in the FASTDB alignment, which arenot matched/aligned with the query sequence are manually corrected. Noother corrections are made for the purposes of the present invention.

b. Fusion Proteins

In certain embodiments, a polypeptide of interest is a fusion protein,and may contain, for example, an affinity tag domain or a reporterdomain. Suitable affinity tags include any amino acid sequence that maybe specifically bound to another moiety, usually another polypeptide,most usually an antibody. Suitable affinity tags include epitope tags,for example, the V5 tag, the FLAG tag, the HA tag (from hemagglutinininfluenza virus), the myc tag, and the like, as is known in the art.Suitable affinity tags also include domains for which, bindingsubstrates are known, e.g., HIS, GST and MBP tags, as is known in theart, and domains from other proteins for which specific bindingpartners, e.g., antibodies, particularly monoclonal antibodies, areavailable. Suitable affinity tags also include any protein-proteininteraction domain, such as a IgG Fc region, which may be specificallybound and detected using a suitable binding partner, e.g. the IgG Fcreceptor. It is expressly contemplated that such a fusion protein maycontain a heterologous N-terminal domain (e.g., an epitope tag) fusedin-frame with a GPCR that has had its N-terminal methionine residueeither deleted or substituted with an alternative amino acid.

Suitable reporter domains include any domain that can report thepresence of a polypeptide. While it is recognized that an affinity tagmay be used to report the presence of a polypeptide using, e.g., alabeled antibody that specifically binds to the tag, light emittingreporter domains are more usually used. Suitable light emitting reporterdomains include luciferase (from, e.g., firefly, Vargula, Renillareniformis or Renilla muelleri), or light emitting variants thereof.Other suitable reporter domains include fluorescent proteins, (frome.g., jellyfish, corals and other coelenterates as such those fromAequoria, Renilla, Pillosarcus, Stylatula species), or light emittingvariants thereof. Light emitting variants of these reporter proteins arevery well known in the art and may be brighter, dimmer, or havedifferent excitation and/or emission spectra, as compared to a nativereporter protein. For example, some variants are altered such that theyno longer appear green, and may appear blue, cyan, yellow, enhancedyellow red (termed BFP, CFP, YFP eYFP and RFP, respectively) or haveother emission spectra, as is known in the art. Other suitable reporterdomains include domains that can report the presence of a polypeptidethrough a biochemical or color change, such as β-galactosidase,β-glucuronidase, chloramphenicol acetyl transferase, and secretedembryonic alkaline phosphatase.

Also as is known in the art, an affinity tags or a reporter domain maybe present at any position in a polypeptide of interest. However, inmost embodiments, they are present at the C- or N-terminal end of apolypeptide of interest.

2. Nucleic Acids Encoding GPCR Polypeptides of Interest

Since the genetic code and recombinant techniques for manipulatingnucleic acid are known, and the amino acid sequences of GPCRpolypeptides of interest described as above, the design and productionof nucleic acids encoding a GPCR polypeptide of interest is well withinthe skill of an artisan. In certain embodiments, standard recombinantDNA technology (Ausubel, et al, Short Protocols in Molecular Biology,3rd ed., Wiley & Sons, 1995; Sambrook, et al., Molecular Cloning: ALaboratory Manual, Second Edition, (1989) Cold Spring Harbor, N.Y.)methods are used. For example, GPCR coding sequences may be isolatedfrom a library of GPCR coding sequence using any one or a combination ofa variety of recombinant methods that do not need to be describedherein. Subsequent substitution, deletion, and/or addition ofnucleotides in the nucleic acid sequence encoding a protein may also bedone using standard recombinant DNA techniques. For example, sitedirected mutagenesis and subcloning may be used tointroduce/delete/substitute nucleic acid residues in a polynucleotideencoding a polypeptide of interest. In other embodiments, PCR may beused. Nucleic acids encoding a polypeptide of interest may also be madeby chemical synthesis entirely from oligonucleotides (e.g., Cello etal., Science (2002) 297:1016-8). In some embodiments, the codons of thenucleic acids encoding polypeptides of interest are optimized forexpression in cells of a particular species, particularly a mammalian,e.g., mouse, rat, hamster, non-human primate, or human, species. In someembodiments, the codons of the nucleic acids encoding polypeptides ofinterest are optimized for expression in cells of a particular species,particularly an amphibian species.

a. Vectors

The invention further provides vectors (also referred to as“constructs”) comprising a subject nucleic acid. In many embodiments ofthe invention, the subject nucleic acid sequences will be expressed in ahost after the sequences have been operably linked to an expressioncontrol sequence, including, e.g. a promoter. The subject nucleic acidsare also typically placed in an expression vector that can replicate ina host cell either as an episome or as an integral part of the hostchromosomal DNA. Commonly, expression vectors will contain selectionmarkers, e.g., tetracycline or neomycin, to permit detection of thosecells transformed with the desired DNA sequences (see, e.g., U.S. Pat.No. 4,704,362, which is incorporated herein by reference). Vectors,including single and dual expression cassette vectors are well known inthe art (Ausubel, et al, Short Protocols in Molecular Biology, 3rd ed.,Wiley & Sons, 1995; Sambrook, et al., Molecular Cloning: A LaboratoryManual, Second Edition, (1989) Cold Spring Harbor, N.Y.). Suitablevectors include viral vectors, plasmids, cosmids, artificial chromosomes(human artificial chromosomes, bacterial artificial chromosomes, yeastartificial chromosomes, etc.), mini-chromosomes, and the like.Retroviral, adenoviral and adeno-associated viral vectors may be used.

A variety of expression vectors are available to those in the art forpurposes of producing a polypeptide of interest in a cell and includeexpression vectors which are commercially available (e.g., fromInvitrogen, Carlsbad, Calif.; Clontech, Mountain View, Calif.;Stratagene, La Jolla, Calif.). Commercially available expression vectorsinclude, by way of non-limiting example, CMV promoter-based vectors. Onesuitable expression vector is pCMV. The expression vector may beadenoviral. An exemplary adenoviral vector may be purchased as AdEasy™from Qbiogene (Carlsbad, Calif.) (He T C et al, Proc Natl Acad Sci USA(1998) 95:2509-2514; and U.S. Pat. No. 5,922,576; the disclosure of eachof which is herein incorporated by reference in its entirety). Othersuitable expression vectors will be readily apparent to those ofordinary skill in the art.

The subject nucleic acids usually comprise an single open reading frameencoding a subject polypeptide of interest, however, in certainembodiments, since the host cell for expression of the polypeptide ofinterest may be a eukaryotic cell, e.g., a mammalian cell, such as ahuman cell, the open reading frame may be interrupted by introns.Subject nucleic acid are typically part of a transcriptional unit whichmay contain, in addition to the subject nucleic acid 3′ and 5′untranslated regions (UTRs) which may direct RNA stability,translational efficiency, etc. The subject nucleic acid may also be partof an expression cassette which contains, in addition to the subjectnucleic acid a promoter, which directs the transcription and expressionof a polypeptide of interest, and a transcriptional terminator.

Eukaryotic promoters can be any promoter that is functional in aeukaryotic host cell, including viral promoters and promoters derivedfrom eukaryotic genes. Exemplary eukaryotic promoters include, but arenot limited to, the following: the promoter of the mouse metallothioneinI gene sequence (Hamer et al., J. Mol. Appl. Gen. 1:273-288, 1982); theTK promoter of Herpes virus (McKnight, Cell 31:355-365, 1982); the SV40early promoter (Benoist et al., Nature (London) 290:304-310, 1981); theyeast gall gene sequence promoter (Johnston et al., Proc. Natl. Acad.Sci. (USA) 79:6971-6975, 1982); Silver et al., Proc. Natl. Acad. Sci.(USA) 81:5951-59SS, 1984), the CMV promoter, the EF-1 promoter,Ecdysone-responsive promoter(s), tetracycline-responsive promoter, andthe like. Viral promoters may be of particular interest as they aregenerally particularly strong promoters. In certain embodiments, apromoter is used that is a promoter of the target pathogen. Promotersfor use in the present invention are selected such that they arefunctional in the cell type (and/or animal) into which they are beingintroduced. In certain embodiments, the promoter is a CMV promoter.

In certain embodiments, a subject vector may also provide for expressionof a selectable marker. Suitable vectors and selectable markers are wellknown in the art and discussed in Ausubel, et al, (Short Protocols inMolecular Biology, 3rd ed., Wiley & Sons, 1995) and Sambrook, et al,(Molecular Cloning: A Laboratory Manual, Third Edition, (2001) ColdSpring Harbor, N.Y.). A variety of different genes have been employed asselectable markers, and the particular gene employed in the subjectvectors as a selectable marker is chosen primarily as a matter ofconvenience. Known selectable marker genes include: the thymidine kinasegene, the dihydrofolate reductase gene, the xanthine-guaninephosphoribosyl transferase gene, CAD, the adenosine deaminase gene, theasparagine synthetase gene, the antibiotic resistance genes, e.g. tetr,ampr, Cmr or cat, kanr or neor (aminoglycoside phosphotransferasegenes), the hygromycin B phosphotransferase gene, and the like. Asmentioned above, polypeptides of interest may be fusion proteins thatcontain an affinity domain and/or a reporter domain. Methods for makingfusions between a reporter or tag and a GPCR, for example, at the C- orN-terminus of the GPCR, are well within the skill of one of skill in theart (e.g. McLean et al, Mol. Pharma. Mol. Pharmacol. 1999 56:1182-91;Ramsay et al., Br. J. Pharmacology, 2001, 315-323) and will not bedescribed any further. It is expressly contemplated that such a fusionprotein may contain a heterologous N-terminal domain (e.g., an epitopetag) fused in-frame with a GPCR that has had its N-terminal methionineresidue either deleted or substituted with an alternative amino acid. Itis appreciated that a polypeptide of interest may first be made from anative polypeptide and then operably linked to a suitable reporter/tagas described above.

The subject nucleic acids may also contain restriction sites, multiplecloning sites, primer binding sites, ligatable ends, recombination sitesetc., usually in order to facilitate the construction of a nucleic acidencoding a polypeptide of interest.

b. Host Cells

The invention further provides host cells comprising a vector comprisinga subject nucleic acid. Suitable host cells include prokaryotic, e.g.,bacterial cells (for example E. coli), as well as eukaryotic cells e.g.an animal cell (for example an insect, mammal, fish, amphibian, bird orreptile cell), a plant cell (for example a maize or Arabidopsis cell),or a fungal cell (for example a S. cerevisiae cell). In certainembodiments, any cell suitable for expression of a polypeptide ofinterest-encoding nucleic acid may be used as a host cell. Usually, ananimal host cell line is used, examples of which are as follows: monkeykidney cells (COS cells), monkey kidney CV1 cells transformed by SV40(COS-7, ATCC CRL 165 1); human embryonic kidney cells (HEK-293 [“293”],Graham et al. J. Gen Virol. 36:59 (1977)); HEK-293T [“293T”] cells; babyhamster kidney cells (BHK, ATCC CCL 10); chinese hamster ovary-cells(CHO, Urlaub and Chasin, Proc. Natl. Acad. Sci. (USA) 77:4216, (1980);Syrian golden hamster cells MCB3901 (ATCC CRL-9595); mouse sertoli cells(TM4, Mather, Biol. Reprod. 23:243-251 (1980)); monkey kidney cells (CV1ATCC CCL 70); african green monkey kidney cells (VERO-76, ATCCCRL-1587); human cervical carcinoma cells (HELA, ATCC CCL 2); caninekidney cells (MDCK, ATCC CCL 34); buffalo rat liver cells (BRL 3A, ATCCCRL 1442); human lung cells (W138, ATCC CCL 75); human liver cells (hepG2, HB 8065); mouse mammary tumor (MMT 060562, ATCC CCL 51); TR1 cells(Mather et al., Annals N.Y. Acad. Sci. 383:44-68 (1982)); NIH/3T3 cells(ATCC CRL-1658); and mouse L cells (ATCC CCL-1). In certain embodiments,melanophores are used. Melanophores are skin cells found in lowervertebrates. Relevant materials and methods will be followed accordingto the disclosure of U.S. Pat. No. 5,462,856 and U.S. Pat. No.6,051,386. These patent disclosures are herein incorporated by referencein their entirety.

Additional cell lines will become apparent to those of ordinary skill inthe art, and a wide variety of cell lines are available from theAmerican Type Culture Collection, 10801 University Boulevard, Manassas,Va. 20110-2209.

C. Screening of Candidate Compounds

1. Generic GPCR Screening Assay Techniques

When a G protein receptor becomes active, it binds to a G protein (e.g.,Gq, Gs, Gi, Gz, Go) and stimulates the binding of GTP to the G protein.The G protein then acts as a GTPase and slowly hydrolyzes the GTP toGDP, whereby the receptor, under normal conditions, becomes deactivated.However, activated receptors continue to exchange GDP to GTP. Anon-hydrolyzable analog of GTP, [³⁵S]GTPγS, can be used to monitorenhanced binding to membranes which express activated receptors. It isreported that [³⁵S]GTPγS can be used to monitor G protein coupling tomembranes in the absence and presence of ligand. An example of thismonitoring, among other examples well-known and available to those inthe art, was reported by Traynor and Nahorski in 1995. A preferred useof this assay system is for initial screening of candidate compoundsbecause the system is generically applicable to all G protein-coupledreceptors regardless of the particular G protein that interacts with theintracellular domain of the receptor.

2. Specific GPCR Screening Assay Techniques

Once candidate compounds are identified using the “generic” Gprotein-coupled receptor assay (i.e., an assay to select compounds thatare agonists or inverse agonists), in some embodiments further screeningto confirm that the compounds have interacted at the receptor site ispreferred. For example, a compound identified by the “generic” assay maynot bind to the receptor, but may instead merely “uncouple” the Gprotein from the intracellular domain.

a. Gs, Gz and Gi.

Gs stimulates the enzyme adenylyl cyclase. Gi (and Gz and Go), on theother hand, inhibit adenylyl cyclase. Adenylyl cyclase catalyzes theconversion of ATP to cAMP; thus, activated GPCRs that couple the Gsprotein are associated with increased cellular levels of cAMP. On theother hand, activated GPCRs that couple Gi (or Gz, Go) protein areassociated with decreased cellular levels of cAMP. See, generally,“Indirect Mechanisms of Synaptic Transmission,” Chpt. 8, From Neuron ToBrain (3^(rd) Ed.) Nichols, J. G. et al eds. Sinauer Associates, Inc.(1992). Thus, assays that detect cAMP can be utilized to determine if acandidate compound is, e.g., an inverse agonist to the receptor (i.e.,such a compound would decrease the levels of cAMP). A variety ofapproaches known in the art for measuring cAMP can be utilized; in someembodiments a preferred approach relies upon the use of anti-cAMPantibodies in an ELISA-based format. Another type of assay that can beutilized is a whole cell second messenger reporter system assay.Promoters on genes drive the expression of the proteins that aparticular gene encodes. Cyclic AMP drives gene expression by promotingthe binding of a cAMP-responsive DNA binding protein or transcriptionfactor (CREB) that then binds to the promoter at specific sites calledcAMP response elements and drives the expression of the gene. Reportersystems can be constructed which have a promoter containing multiplecAMP response elements before the reporter gene, e.g., β-galactosidaseor luciferase. Thus, an activated Gs-linked receptor causes theaccumulation of cAMP that then activates the gene and expression of thereporter protein. The reporter protein such as β-galactosidase orluciferase can then be detected using standard biochemical assays (Chenet al. 1995).

b. Go and Gq.

Gq and Go are associated with activation of the enzyme phospholipase C,which in turn hydrolyzes the phospholipid PIP₂, releasing twointracellular messengers: diacyclglycerol (DAG) and inositol1,4,5-triphosphate (IP₃). Increased accumulation of IP₃ is associatedwith activation of Gq- and Go-associated receptors. See, generally,“Indirect Mechanisms of Synaptic Transmission,” Chpt. 8, From Neuron ToBrain (3^(rd) Ed.) Nichols, J. G. et al eds. Sinauer Associates, Inc.(1992). Assays that detect IP₃ accumulation can be utilized to determineif a candidate compound is, e.g., an inverse agonist to a Gq- orGo-associated receptor (i.e., such a compound would decrease the levelsof IP₃). Gq-associated receptors can also been examined using an APIreporter assay in that Gq-dependent phospholipase C causes activation ofgenes containing API elements; thus, activated Gq-associated receptorswill evidence an increase in the expression of such genes, wherebyinverse agonists thereto will evidence a decrease in such expression,and agonists will evidence an increase in such expression. Commerciallyavailable assays for such detection are available.

3. GPCR Fusion Protein

The use of an endogenous, constitutively active GPCR or anon-endogenous, constitutively activated GPCR, for use in screening ofcandidate compounds for the direct identification of inverse agonists oragonists provides an interesting screening challenge in that, bydefinition, the receptor is active even in the absence of an endogenousligand bound thereto. Thus, in order to differentiate between, e.g., thenon-endogenous receptor in the presence of a candidate compound and thenon-endogenous receptor in the absence of that compound, with an aim ofsuch a differentiation to allow for an understanding as to whether suchcompound may be an inverse agonist or agonist or have no affect on sucha receptor, in some embodiments it is preferred that an approach beutilized that can enhance such differentiation. In some embodiments, apreferred approach is the use of a GPCR Fusion Protein.

Generally, once it is determined that a non-endogenous GPCR has beenconstitutively activated using the assay techniques set forth above (aswell as others known to the art-skilled), it is possible to determinethe predominant G protein that couples with the endogenous GPCR.Coupling of the G protein to the GPCR provides a signaling pathway thatcan be assessed. In some embodiments it is preferred that screening takeplace using a mammalian or a melanophore expression system, as such asystem will be expected to have endogenous G protein therein. Thus, bydefinition, in such a system, the non-endogenous, constitutivelyactivated GPCR will continuously signal. In some embodiments it ispreferred that this signal be enhanced such that in the presence of,e.g., an inverse agonist to the receptor, it is more likely that it willbe able to more readily differentiate, particularly in the context ofscreening, between the receptor when it is contacted with the inverseagonist.

The GPCR Fusion Protein is intended to enhance the efficacy of G proteincoupling with the GPCR. The GPCR Fusion Protein may be preferred forscreening with either an endogenous, constitutively active GPCR or anon-endogenous, constitutively activated GPCR because such an approachincreases the signal that is generated in such screening techniques.This is important in facilitating a significant “signal to noise” ratio;such a significant ratio is preferred for the screening of candidatecompounds as disclosed herein.

The construction of a construct useful for expression of a GPCR FusionProtein is within the purview of those having ordinary skill in the art.Commercially available expression vectors and systems offer a variety ofapproaches that can fit the particular needs of an investigator.Important criteria in the construction of such a GPCR Fusion Proteinconstruct include but are not limited to, that the GPCR sequence and theG protein sequence both be in-frame (preferably, the sequence for theendogenous GPCR is upstream of the G protein sequence), and that the“stop” codon of the GPCR be deleted or replaced such that uponexpression of the GPCR, the G protein can also be expressed. The GPCRcan be linked directly to the G protein, or there can be spacer residuesbetween the two (preferably, no more than about 12, although this numbercan be readily ascertained by one of ordinary skill in the art). Basedupon convenience, it is preferred to use a spacer. In some embodiments,it is preferred that the G protein that couples to the non-endogenousGPCR will have been identified prior to the creation of the GPCR FusionProtein construct. As noted above, activated GPCRs that couple to Gi, Gzand Go are expected to inhibit the formation of cAMP making assays basedupon these types of GPCRs challenging (i.e., the cAMP signal decreasesupon activation, thus making the direct identification of, e.g.,agonists (which would further decrease this signal) challenging). Aswill be disclosed herein, it has been ascertained that for these typesof receptors, it is possible to create a GPCR Fusion Protein that is notbased upon the GPCR's endogenous G protein, in an effort to establish aviable cyclase-based assay. Thus, for example, an endogenous Gi coupledreceptor can be fused to a Gs protein—such a fusion construct, uponexpression, “drives” or “forces” the endogenous GPCR to couple with,e.g., Gs rather than the “natural” Gi protein, such that a cyclase-basedassay can be established. Thus, for Gi, Gz and Go coupled receptors, insome embodiments it is preferred that when a GPCR Fusion Protein is usedand the assay is based upon detection of adenylyl cyclase activity, thatthe fusion construct be established with Gs (or an equivalent G proteinthat stimulates the formation of the enzyme adenylyl cyclase).

TABLE C Effect of IP₃ Accumulation Effect of Effect of cAMP upon cAMPProduction upon Activation Production Activation of of GPCR (i.e., uponEffect on IP₃ GPCR (i.e., constitutive contact Accumulation constitutiveactivation or with an upon G activation or agonist Inverse contact withan protein agonist binding) binding) Agonist Inverse Agonist Gs IncreaseN/A Decrease N/A Gi Decrease N/A Increase N/A Gz Decrease N/A IncreaseN/A Go Decrease Increase Increase Decrease Gq N/A Increase N/A Decrease

Equally effective is a G Protein Fusion construct that utilizes a GqProtein fused with a Gs, Gi, Gz or Go Protein. In some embodiments apreferred fusion construct can be accomplished with a Gq Protein whereinthe first six (6) amino acids of the G-protein α-subunit (“Gαq”) isdeleted and the last five (5) amino acids at the C-terminal end of Gαqis replaced with the corresponding amino acids of the Gα of the Gprotein of interest. For example, a fusion construct can have a Gq (6amino acid deletion) fused with a Gi Protein, resulting in a “Gq/GiFusion Construct”. This fusion construct will force the endogenous Gicoupled receptor to couple to its non-endogenous G protein, Gq, suchthat the second messenger, for example, inositol triphosphate ordiacylgycerol, can be measured in lieu of cAMP production.

4. Co-transfection of a Target Gi Coupled GPCR with a Signal-Enhancer GsCoupled GPCR (cAMP Based Assays)

A Gi coupled receptor is known to inhibit adenylyl cyclase, and,therefore, decreases the level of cAMP production, which can make theassessment of cAMP levels challenging. In certain embodiments, aneffective technique in measuring the decrease in production of cAMP asan indication of activation of a receptor that predominantly couples Giupon activation can be accomplished by co-transfecting a signalenhancer, e.g., a non-endogenous, constitutively activated receptor thatpredominantly couples with Gs upon activation (e.g., TSHR-A623I; seeinfra), with the Gi linked GPCR. As is apparent, activation of a Gscoupled receptor can be determined based upon an increase in productionof cAMP. Activation of a Gi coupled receptor leads to a decrease inproduction cAMP. Thus, the co-transfection approach is intended toadvantageously exploit these “opposite” affects. For example,co-transfection of a non-endogenous, constitutively activated Gs coupledreceptor (the “signal enhancer”) with expression vector alone provides abaseline cAMP signal (i.e., although the Gi coupled receptor willdecrease cAMP levels, this “decrease” will be relative to thesubstantial increase in cAMP levels established by constitutivelyactivated Gs coupled signal enhancer). By then co-transfecting thesignal enhancer with the “target receptor”, an inverse agonist of the Gicoupled target receptor will increase the measured cAMP signal, while anagonist of the Gi coupled target receptor will decrease this signal.

Candidate compounds that are directly identified using this approachshould be assessed independently to ensure that these do not target thesignal enhancing receptor (this can be done prior to or after screeningagainst the co-transfected receptors).

Composition/Formulation and Methods of Treatment

A GPR119 agonist can be formulated into pharmaceutical compositions andmedicaments for use in accordance with the present invention usingtechniques well known in the art. Proper formulation is dependent on theroute of administration chosen. In certain embodiments, saidadministration is to a non-human vertebrate or to a non-human mammal.

As relates to therapies of the present invention, namely therapiesrelating to a GPR119 agonist, the compounds according to the inventioncan be administered in any suitable way. Suitable routes ofadministration include oral, nasal, rectal, transmucosal, transdermal,or intestinal administration, parenteral delivery, includingintramuscular, subcutaneous, intramedullary injections, as well asintrathecal, direct intraventricular, intravenous, intraperitoneal,intranasal, intrapulmonary (inhaled) or intraocular injections usingmethods known in the art. Other suitable routes of administration areaerosol and depot formulation. Sustained release formulations,particularly depot, of the invented medicaments are expresslycontemplated. In certain preferred embodiments, the compounds accordingto the present invention are administered orally. The compoundsaccording to the present invention can be made up in solid or liquidform, such as tablets, capsules, powders, syrups, elixirs and the like,aerosols, sterile solutions, suspensions or emulsions, and the like. Incertain embodiments, the GPR119 agonist is administered orally.

Formulations for oral administration may be in the form of aqueoussolutions and suspensions, in addition to solid tablet and capsuleformulations. The aqueous solutions and suspensions may be prepared fromsterile powders or granules. The compounds may be dissolved in water,polyethylene glycol, propylene glycol, ethanol, corn oil, cottonseedoil, peanut oil, sesame oil, benzyl alcohol, sodium chloride, and/orvarious buffers. Other adjuvants are well and widely known in the art.

Pharmaceutical compositions of the GPR119 agonist may be prepared bymethods well known in the art, e.g., by means of conventional mixing,dissolving, granulation, dragee-making, levigating, emulsifying,encapsulating, entrapping, lyophilizing processes or spray drying.

Pharmaceutical compositions for use in accordance with the presentinvention may be formulated in conventional manner using one or morephysiologically acceptable carriers comprising excipients andauxiliaries which facilitate processing of the active compounds intopreparations which can be used pharmaceutically. Suitablepharmaceutically acceptable carriers are available to those in the art(see, e.g., Remington: The Science and Practice of Pharmacy, (Gennaro etal., eds.), 20^(th Edition,) 2000, Lippincott Williams & Wilkins; andHandbook of Pharmaceutical Excipients (Rowe et al., eds), 4^(th)Edition, 2003, Pharmaceutical Press; the disclosure of each of which isherein incorporated by reference in its entirety). Proper formulation isdependent upon the route of administration chosen. The term “carrier”material or “excipient” material herein means any substance, not itselfa therapeutic agent, used as a carrier and/or dilutent and/or adjuvant,or vehicle for delivery of a therapeutic agent to a subject or added toa pharmaceutical composition to improve its handling or storageproperties or to permit or facilitate formation of a dose unit of thecomposition into a discrete article such as a capsule or tablet suitablefor oral administration. Excipients can include, by way of illustrationand not limitation, diluents, disintegrants, binding agents, adhesives,wetting agents, polymers, lubricants, glidants, substances added to maskor counteract a disagreeable taste or odor, flavors, dyes, fragrances,and substances added to improved appearance of the composition.Acceptable excipients include stearic acid, magnesium stearate,magnesium oxide, sodium and calcium salts of phosphoric and sulfuricacids, magnesium carbonate, talc, gelatin, acacia gum, sodium alginate,pectin, dextrin, mannitol, sorbitol, lactose, sucrose, starches,gelatin, cellulosic materials, such as cellulose esters of alkanoicacids and cellulose alkyl esters, low melting wax cocoa butter orpowder, polymers, such as polyvinyl-pyrrolidone, polyvinyl alcohol, andpolytheylene glycols, and other pharmaceutically acceptable materials.The components of the pharmaceutical composition can be encapsulated ortableted for convenient administration.

Pharmaceutically acceptable refers to those properties and/or substanceswhich are acceptable to the patient from a pharmacological/toxicologicalpoint of view and to the manufacturing pharmaceutical chemist from aphysical/chemical point of view regarding composition, formulation,stability, patient acceptance and bioavailability.

Dragee cores are provided with suitable coatings. For this purpose,concentrated sugar solutions may be used which may optionally containgum Arabic, talc, polyvinyl pyrrolidone, carbopol gel, polyethyleneglycol, and/or titanium dioxide, lacquer solutions, and suitable organicsolvents or solvent mixtures. Dyestuffs or pigments may be added to thetablets or dragee coatings for identification or to characterizedifferent combinations of active compound doses.

Pharmaceutical compositions which can be used orally include push-fitcapsules made of gelatin, as well as soft, sealed capsules made ofgelatin and a plasticizer, such as glycerol or sorbitol. The push-fitcapsules can contain the active ingredients in admixture with a fillersuch as lactose, a binder such as starch, and/or a lubricant such astalc or magnesium stearate and, optionally, stabilizers. In softcapsules, the active compounds may be dissolved or suspended in suitableliquids, such as fatty oils, liquid paraffin, liquid polyethyleneglycols, cremophor, capmul, medium or long chain mono-, di- ortriglycerides. Stabilizers may be added in these formulations, also.

Additionally, a GPR119 agonist may be delivered using asustained-release system. Various sustained-release materials have beenestablished and are well known to those skilled in the art.Sustained-release tablets or capsules are particularly preferred. Forexample, a time delay material such as glyceryl monostearate or glyceryldistearate may be employed. The dosage form may also be coated by thetechniques described in the U.S. Pat. Nos. 4,256,108, 4,166,452, and4,265,874 to form osmotic therapeutic tablets for controlled release.

It is expressly contemplated that therapies of the present invention,namely therapies relating to a GPR119 agonist, may be administered orprovided alone or in combination with one or more other pharmaceuticallyor physiologically acceptable compound. In one aspect of the presentinvention, the other pharmaceutically or physiologically acceptablecompound is not a GPR119 agonist. In one aspect of the presentinvention, the other pharmaceutically or physiologically acceptablecompound is a pharmaceutical agent selected from the group consisting ofcalcium, vitamin D, estrogen, tibolone, selective estrogen receptormodulator (SERM; e.g., raloxifene, tamoxifen), biphosphonate (e.g.,etidronate, alendronate, risedronate), calcitonin, 1α-hydroxylatedmetabolite of vitamin D, fluoride, thiazide, anabolic steroid,ipriflavone, vitamin K, parathyroid hormone (PTH), strontium, statin,osteoprotererin, EP4 receptor selective agonist, cannabinoid receptortype 2 (CB2) selective agonist, and p38 MAP kinase inhibitor. (See,e.g., World Health Organization Technical Report Series 921 (2003),Prevention and Management of Osteoporosis.)

In one aspect, the present invention features a composition comprisingor consisting essentially of an amount of a GPR119 agonist according tothe present invention. In one aspect, the present invention features apharmaceutical composition comprising or consisting essentially of anamount of a GPR119 agonist according to the present invention and atleast one pharmaceutically acceptable carrier.

In one aspect, the present invention features a composition comprisingor consisting essentially of an amount of a GPR119 agonist according tothe present invention. In one aspect, the present invention features apharmaceutical composition comprising or consisting essentially of anamount of a GPR119 agonist according to the present invention and atleast one pharmaceutically acceptable carrier. The present inventionalso relates to a dosage form of the composition or of thepharmaceutical composition wherein the GPR119 agonist is in an amountsufficient to give an effect in treating or preventing a conditioncharacterized by low bone mass, such as osteoporosis, and/or inincreasing bone mass in an individual.

In one aspect, the present invention features a composition comprisingor consisting essentially of an amount of a GPR119 agonist according tothe present invention. In one aspect, the present invention features apharmaceutical composition comprising or consisting essentially of anamount of a GPR119 agonist according to the present invention and atleast one pharmaceutically acceptable carrier. The present inventionalso relates to a dosage form of the composition or of thepharmaceutical composition wherein the GPR119 agonist is in an amountsufficient to give an effect in increasing a GIP level in an individual.

Pharmaceutical compositions suitable for use in the present inventioninclude compositions wherein the active ingredients are contained in anamount to achieve their intended purpose. In some embodiments, apharmaceutical composition of the present invention is understood to beuseful for treating or preventing a condition characterized by low bonemass, such as osteoporosis, or for increasing bone mass in anindividual. Conditions characterized by low bone mass are according tothe present invention. In some embodiments, a pharmaceutical compositionof the present invention is understood to be useful for increasing a GIPlevel in an individual. As relates to the present invention,determination of the amount of a GPR119 agonist sufficient to achieve anintended purpose according to the invention is well within thecapability of those skilled in the art, especially in light of thedetailed disclosure provided herein.

The data obtained from animal studies, including but not limited tostudies using mice, rats, rabbits, pigs, and non-human primates, can beused in formulating a range of dosage for use in humans. In general, oneskilled in the art understands how to extrapolate in vivo data obtainedin an animal model system to another, such as a human. In somecircumstances, these extrapolations may merely be based on the weight ofthe animal model in comparison to another, such as a human; in othercircumstances, these extrapolations are not simply based on weights butrather incorporate a variety of factors. Representative factors includethe type, age, weight, sex, diet and medical condition of the patient,the severity of the disease, the route of administration,pharmacological considerations such as the activity, efficacy,pharmacokinetic and toxicology profiles of the particular compoundemployed, whether a drug delivery system is utilized, on whether anacute or chronic disease state is being treated or prophylaxis isconducted or on whether further active compounds are administered inaddition to the compounds of the present invention and as part of a drugcombination. The dosage regimen for treating a disease condition withthe compounds and/or compositions of this invention is selected inaccordance with a variety factors as cited above. Thus, the actualdosage regimen employed may vary widely and therefore may deviate from apreferred dosage regimen and one skilled in the art will recognize thatdosage and dosage regimen outside these typical ranges can be testedand, where appropriate, may be used in the methods of this invention.

An exemplary animal model system is the rat ovariectomy (OVX) bone lossmodel. The ovariectomized rat is an excellent preclinical animal modelthat correctly emulates the important clinical feature of the estrogendepleted human skeleton and the response of therapeutic agents. In thismodel, a therapeutic efficacy is achieved when the bone loss associatedwith ovariectomy is partially or completely prevented. (See, e.g.,Bollag et al, Mol Cell Endocrinol (2001) 177:35-41; and Jee et al, JMusculoskel Neuron Interact (2001) 1:193-207.) In certain embodiments,therapeutic efficacy is achieved when the bone loss associated withovariectomy is at least about 10% prevented, at least about 20%prevented, at least about 30% prevented, at least about 40% prevented,at least about 50% prevented, at least about 60% prevented, at leastabout 70% prevented, at least about 75% prevented, at least about 80%prevented, at least about 85% prevented, at least about 90% prevented,at least about 95% prevented, or 100% prevented.

An additional exemplary animal model system is increase of a blood GIPlevel after glucose challenge in mice. In certain embodiments, the bloodGIP level is a plasma GIP level. In certain embodiments, the GIP levelis a glucose-independent GIP level. In certain embodiments, the GIPlevel is a glucose-dependent GIP level. In certain embodiments, the GIPis total GIP. In certain embodiments, the total GIP is measured using acentrally or C-terminally directed assay. In certain embodiments, theGIP is bioactive GIP. In certain embodiments, the bioactive GIP ismeasured using an N-terminal-specific assay. In certain embodiments, thebioactive GIP has activity for promoting bone formation. In certainembodiments, therapeutic efficacy is achieved when the blood GIP levelis increased by at least about 10%, at least about 25%, at least about50%, at least about 100%, at least about 150%, at least about 200%, atleast about 300%, at least about 400%, or at least about 500%.

Dosage amount and interval may be adjusted in order to provide anintended therapeutic effect. It will be appreciated that the exactdosage of a GPR119 agonist in accordance with the present invention willvary depending on the GPR119 agonist, its potency, the mode ofadministration, the age and weight of the patient and the severity ofthe condition to be treated. The exact formulation, route ofadministration and dosage can be chosen by the individual physician inview of the patient's condition. By way of illustration and notlimitation, an amount of a GPR119 agonist in accordance with the presentinvention is less than about 0.001 mg/kg body weight, less than about0.005 mg/kg body weight, less than about 0.01 mg/kg body weight, lessthan about 0.05 mg/kg body weight, less than about 0.1 mg/kg bodyweight, less than about 0.5 mg/kg body weight, less than about 1 mg/kgbody weight, less than about 5 mg/kg body weight, less than about 10mg/kg body weight, less than about 50 mg/kg body weight, or less thanabout 100 mg/kg body weight. In certain embodiments, an amount of aGPR119 agonist in accordance with the present invention is less thanabout 0.001-100 mg/kg body weight, less than about 0.001-50 mg/kg bodyweight, less than about 0.001-10 mg/kg body weight, less than about0.001-5 mg/kg body weight, less than about 0.001-1 mg/kg body Weight,less than about 0.001 to 0.5 mg/kg body weight, less than about0.001-0.1 mg/kg body weight, less than about 0.001-0.05 mg/kg bodyweight, less than about 0.001-0.01 mg/kg body weight, or less than about0.001-0.005 mg/kg body weight.

A preferred dosage range for the amount of a modulator of the invention(e.g. a GPR119 agonist), which can be administered on a daily or regularbasis to achieve desired results is 0.1-100 mg/kg body mass. Otherpreferred dosage range is 0.1-30 mg/kg body mass. Other preferred dosagerange is 0.1-10 mg/kg body mass. Other preferred dosage range is 0.1-3.0mg/kg body mass. Of course, these daily dosages can be delivered oradministered in small amounts periodically during the course of a day.It is noted that these dosage ranges are only preferred ranges and arenot meant to be limiting to the invention.

Dosage amount and interval may be adjusted individually to provideplasma levels of a GPR119 agonist according to the present inventionwhich achieve an intended therapeutic effect. Dosage intervals can alsobe determined using the value for a selected range of GPR119 agonistconcentration so as to achieve the intended therapeutic effect. A GPR119agonist should be administered using a regimen that maintains plasmalevels within the selected range of GPR119 agonist concentration for10-90% of the time, preferably between 30-99% of the time, and mostpreferably between 50-90% of the time. In cases of local administrationor selective uptake, the range of GPR119 agonist concentration providingthe intended therapeutic effect may not be related to plasmaconcentration.

The amount of composition administered will, of course, be dependent onthe individual being treated, on the individual's weight, the severityof the affliction, the manner of administration, and the judgement ofthe prescribing physician.

In one aspect, the present invention accordingly features a method oftreating or preventing a condition characterized by low bone mass, suchas osteoporosis, or of increasing bone mass comprising administering toan individual in need thereof a therapeutically effective amount of acomposition comprising or consisting essentially of an amount of aGPR119 agonist according to the present invention. In certainembodiments, the composition is a pharmaceutical composition.

In one aspect, the present invention relates to a method of treating orpreventing a condition characterized by low bone mass, such asosteoporosis, or of increasing bone mass comprising administering to anindividual in need thereof a therapeutically effective amount of acomposition comprising or consisting essentially of an amount of aGPR119 agonist according to the present invention. In a related aspect,the present invention features said method wherein the GPR119 agonist isadministered in an amount sufficient to give an effect in increasing aGIP level in the individual. In certain embodiments, the composition isa pharmaceutical composition.

Therapies of the present invention, namely therapies relating to aGPR119 agonist are useful in treating or preventing a conditioncharacterized by low bone mass in an individival and in increasing bonemass in an individual.

Conditions characterized by low bone mass include but are not limited toosteopenia, osteoporosis, rheumatoid arthritis, osteoarthritis,periodontal disease, alveolar bone loss, osteotomy bone loss, childhoodidiopathic bone loss, Paget's disease, bone loss due to metastaticcancer, osteolytic lesions, curvature of the spine, and loss of height.In certain embodiments, the condition characterized by low bone mass isosteoporosis. In certain embodiments, the condition characterized by lowbone mass is osteoporosis. In certain embodiments, osteoporosis isprimary osteoporosis. In certain embodiments, osteoporosis is secondaryosteoporosis. Conditions characterized by low bone mass also include butare not limited to long-term complications of osteoporosis such ascurvature of the spine, loss of height and prosthetic surgery. It isunderstood that conditions characterized by low bone mass can beincluded in embodiments individually or in any combination. In certainembodiments, the condition characterized by low bone mass is primaryosteoporosis.

In certain embodiments, the individual in need of increased bone masshas a bone mineral density (BMD) of greater than 1 (T-score <−1),greater than or equal to 1.5 (T-score ≦−1.5), greater than or equal to 2(T-score ≦−2) or greater than or equal to 2.5 (T-score ≦−2.5) standarddeviations below the young adult reference mean. In certain embodiments,the individual in need of increased bone mass is in need of treatment ofbone fracture. In certain embodiments, the individual in need oftreatment of a bone fracture has a traumatic bone fracture, a long-termbone fracture, or an osteoporotic bone fracture. In certain embodiments,the individual is in need of treatment for a bone disease. In certainembodiments, the individual in need of treatment for a bone disease hasosteopenia, osteoporosis, rheumatoid arthritis, osteoarthritis,periodontal disease, alveolar bone loss, osteotomy bone loss, childhoodidiopathic bone loss, Paget's disease, bone loss due to metastaticcancer, osteolytic lesions, curvature of the spine, or loss of height.In certain embodiments, the individual in need of treatment for a bonedisease has osteoporosis. In certain embodiments, osteoporosis isprimary osteoporosis. In certain embodiments, osteoporosis is secondaryosteoporosis. Destructive bone disorders that can be treated accordingto the invention include but are not limited to osteoporosis,osteoarthritis, and osteolytic lesions such as those caused byneoplastic disease, radiotherapy, or chemotherapy. In certainembodiments, osteoporosis is primary osteoporosis. In certainembodiments, osteoporosis is secondary osteoporosis.

Therapies of the present invention, namely therapies relating to aGPR119 agonist are additionally useful in enhancing bone healingfollowing facial reconstruction, maxillary reconstruction, mandibularreconstruction, periodontal disease or tooth extraction, enhancing longbone extension, enhancing prosthetic ingrowth or increasing bonesynostosis in an individual.

In certain embodiments, the individual is a vertebrate. In certainembodiments, the individual that is a vertebrate is a fish, anamphibian, a reptile, a bird or a mammal. In certain embodiments, theindividual or vertebrate is a mammal. In certain embodiments, theindividual or vertebrate that is a mammal is a mouse, a rat, a hamster,a rabbit, a pig, a dog, a cat, a horse, a cow, a sheep, a goat, anon-human mammal, a non-human primate or a human. In certainembodiments, the individual is a human. In certain embodiments, thehuman is a post-menopausal woman or a man over the age of 50.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, practice the present invention toits fullest extent. The foregoing detailed description is given forclearness of understanding only, and no unnecessary limitation should beunderstood therefrom, as modifications within the scope of the inventionmay become apparent to those skilled in the art.

This application claims the benefit of priority from the followingprovisional patent application, filed via U.S. Express Mail with theUnited States Patent and Trademark Office on the indicated date: U.S.Provisional Patent Application No. 60/791,550, filed Apr. 11, 2006. Thedisclosure of the foregoing provisional patent application is hereinincorporated by reference in its entirety.

Throughout this application, various publications, patents and patentapplications are cited. The disclosures of these publications, patentsand patent applications referenced in this application are hereinincorporated by reference in their entirety into the present disclosure.Citation herein by Applicant of a publication, patent, or patentapplication is not an admission by Applicant of said publication,patent, or patent application as prior art.

EXAMPLES

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, practice the present invention toits fullest extent. The following detailed examples are to be construedas merely illustrative, and not limitations of the preceding disclosurein any way whatsoever. Those skilled in the art will promptly recognizeappropriate variations from the procedures.

Example 1 Pharmacodynamic Analysis of an Effect of Administration ofGPR119 Agonist on Blood GIP Level in Wild-Type Mice

A. C57blk/6 male mice were fasted for 18 hours, and randomly assignedinto fourteen groups with n=6 for each group. Mice were administered perorally with vehicle (PET; 80% PEG400, 10% ethanol, 10% Tween80) or witha GPR119 agonist in accordance with the present invention (Compound 1;(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine)at 20 mg/kg, as indicated in FIG. 1A. Thirty minutes after treatment, aglucose bolus at 3 g/kg were delivered per orally, and plasma werecollected at 0 (no glucose bolus), 2, 5, 10, 20, 40 and 60 minutes afterglucose bolus. Plasma GIP levels were determined by using a rodent GIPELISA kit purchased from Linco Research Laboratory [Rat/Mouse GastricInhibitory Polypeptide (Total) ELISA Catalog #EZRMGIP-55K], followinginstructions provided by the supplier. From the results shown in FIG.1A, it is apparent that administration of the GPR119 agonist increasedboth a glucose-dependent and a glucose-independent level of GIP in theblood of the mice. Compound 1 stimulated plasma total GIP in the mice.Compound 1 is identical to a compound disclosed in International PatentApplication No. PCT/US2004/001267 (published as WO 2004/065380).

B. C57blk/6 male mice were fasted for 18 hours, and randomly assignedinto fourteen groups with n=6 for each group. Mice were administered perorally with vehicle (20% hydroxypropyl-β-cyclodextrin (HPCD)) or with aGPR119 agonist in accordance with the present invention (Compound 3) at10 mg/kg, as indicated in FIG. 1B. Thirty minutes after treatment, aglucose bolus at 3 g/kg were delivered per orally, and plasma werecollected at 0 (no glucose bolus), 5, 10, 20, 60 and 120 minutes afterglucose bolus. Plasma GIP levels were determined by using a rodent GIPELISA kit purchased from Linco Research Laboratory [Rat/Mouse GastricInhibitory Polypeptide (Total) ELISA Catalog #EZRMGIP-55K], followinginstructions provided by the supplier. Statistical analysis wasperformed using Excel program. Mean values of GIP concentration werecalculated based on results with six mice in each group and shown asmean±SEM. From the results shown in FIG. 1B, it is apparent thatadministration of the GPR119 agonist increased both a glucose-dependentand a glucose-independent level of GIP in the blood of the mice.Compound 3 stimulated plasma total GIP in the mice. Compound 3 isidentical to a compound disclosed in International Patent ApplicationNo. PCT/US2004/022327 (published as WO 2005/007647).

C. C57blk/6 male mice were fasted for 18 hours, and randomly assignedinto fourteen groups with n=6 for each group. Mice were administered perorally with vehicle (20% hydroxypropyl-β-cyclodextrin (HPCD)) or with aGPR119 agonist in accordance with the present invention (Compound 3) at1, 3, or 10 mg/kg. Thirty minutes after treatment, a glucose bolus at 3g/kg was delivered per orally, and plasma were collected at 0 (noglucose bolus) or 5 minutes after glucose bolus. Plasma GIP levels weredetermined by using a rodent GIP ELISA kit purchased from Linco ResearchLaboratory [Rat/Mouse Gastric Inhibitory Peptide (Total) ELISA Catalog#EZRMGIP-55K], following instructions provided by the supplier.Statistical analysis was performed using Excel program. Mean values ofGIP concentration were calculated based on results with six mice in eachgroup and are shown in FIG. 1C. From FIG. 1C, it is apparent that theGPR119 agonist (Compound 3) stimulated plasma total GIP in the mice in adose-dependent manner. Compound 3 is identical to a compound disclosedin International Patent Application No. PCT/US2004/022327 (published asWO 2005/007647).

Example 2 Effect of Administration of GPR119 Agonist on Blood GIP Levelin GPR119-Deficient (Knockout) Mice Compared to Wild-Type Mice

A. GPR119-deficient male mice and wild-type littermates were fasted for18 hours. Mice were administered per orally with vehicle (PET; 80%PEG400, 10% ethanol, 10% Tween80) or with a GPR119 agonist in accordancewith the present invention (Compound 1;(2-Fluoro-4-methanesulfonyl-phenyl)-{6-[4-(3-isopropyl-[1,2,4]oxadiazol-5-yl)-piperidin-1-yl]-5-nitro-pyrimidin-4-yl}-amine)at 20 mg/kg, as indicated (n=5). Thirty minutes after treatment, blood(100 microliter) was collected via retro orbital vein of the eye (time0) followed by a glucose bolus at 3 g/kg (per orally). Five minutesafter delivering glucose, another blood sample (100 microliter) wascollected (time 5 minutes). Plasma were collected after centrifugationand GIP levels were determined by using a rodent GIP ELISA kit purchasedfrom Linco Research Laboratory [Rat/Mouse Gastric Inhibitory Polypeptide(Total) ELISA Catalog #EZRMGIP-55K], following instructions provided bythe supplier. From the results shown in FIG. 2A, it is apparent thatfunctional GPR119 receptor was necessary for the administered GPR119agonist to increase a glucose-independent level and a glucose-dependentlevel of GIP in the blood of the mice. Compound 1 stimulated plasmatotal GIP in the wild-type mice. Compound 1 is identical to a compounddisclosed in International Patent Application No. PCT/US2004/001267(published as WO 2004/065380).

B. GPR119-deficient male mice and wild-type littermates were fasted for18 hours. Mice were administered per orally with vehicle (40%hydroxypropyl-β-cyclodextrin (HPCD)) or with a GPR119 agonist inaccordance with the present invention (Compound 2) at 30 mg/kg, asindicated (n=5). Thirty minutes after treatment, blood (100 microliter)was collected via retro orbital vein of the eye (time 0) followed by aglucose bolus at 3 g/kg (per orally). Five minutes after deliveringglucose, another blood sample (100 microliter) was collected (time 5minutes). Plasma were collected after centrifugation and GIP levels weredetermined by using a rodent GIP ELISA kit purchased from Linco ResearchLaboratory [Rat/Mouse Gastric Inhibitory Polypeptide (Total) ELISACatalog #EZRMGIP-55K], following instructions provided by the supplier.Mean values of GIP concentration were calculated based on results withfive mice in each group. From the results shown in FIG. 2B, it isapparent that functional GPR119 receptor was necessary for theadministered GPR119 agonist to increase a glucose-independent level anda glucose-dependent level of GIP in the blood of the mice. Compound 2stimulated plasma total GIP in the wild-type mice. Compound 2 isidentical to a compound disclosed in International Patent ApplicationNo. PCT/US2004/022417 (published as WO 2005/007658).

Example 3 Effect of Administration OF GPR119 Agonist on Bone Mass inOvariectomized Rats

A GPR119 agonist in accordance with the present invention can be shownto be effective in treating or preventing a condition characterized bylow bone mass, such as osteoporosis, and/or in increasing bone mass inan individual using the in vivo ovariectomized (OVX) rat model describedbelow (see, e.g., Bollag et al, Mol Cell Endocrinol (2001) 177:35-41).

Twenty virgin female OVX and 20 virgin non-OVX Sprague-Dawley rats(150-175 g), age 8 weeks, are purchased from Harlan Sprague-Dawley, Inc.(Indianapolis, Ind.). Animals are fed ad libitum on a normal commercialpellet diet, Teklab Rodent diet (1.46% calcium), with free access towater. The rats are randomly divided into four weight-matchedexperimental groups and selected to receive per orally vehicle or aGPR119 agonist in accordance with the present invention. Treatment iscontinued on a daily basis for 6 weeks.

1. Control. Ten non-OVX rats are administered per orally vehicle.

2. Control+Treatment. Ten non-OVX rats are administered per orallyGPR119 agonist.

3. OVX. Ten OVX rats are administered per orally vehicle.

4. OVX+Treatment. Ten OVX rats are administered per orally GPR119agonist. The rats are weighed daily and length measured at baseline andagain at 6 weeks. Dual energy X-ray absorptiometry (DXA) using a HologicQDR 1000/W (Waltham, Mass.) is performed on all animals prior toinitiation of treatment and at 6 weeks, and data is analyzed using thesoftware Rat Whole Body version 5.53. Bone mineral density (BMD) isdetermined at the spine.

The percent change in vertebral bone density after 6 weeks of treatmentis determined. It is shown that administration of a GPR119 agonistattenuates the negative effects of ovariectomy on vertebral bonedensity. Attenuation of the negative effects of ovariectomy on vertebralbone density is indicative of the treatment having efficacy in treatingor preventing a condition characterized by low bone mass, such asosteoporosis, and/or in increasing bone mass in an individual.

Example 4 Effect of Administration of GPR119 Agonist on Bone FractureHealing

A GPR119 agonist in accordance with the present invention can be shownto be effective in treatment of bone fracture using the in viva assaydescribed below.

Fracture Technique

Sprague-Dawley rats at 3 months of age are anesthetized with Ketamine. A1 cm incision is made on the anteromedial aspect of the proximal part ofthe right tibia or femur. The following describes the tibial surgicaltechnique. The incision is carried through to the bone, and a 1 mm holeis drilled 4 mm proximal to the distal aspect of the tibial tuberosity 2mm medial to the anterior ridge. Intramedullary nailing is performedwith a 0.8 mm stainless steel tube (maximum load 36.3 N, maximumstiffness 61.8 N/mm, tested under the same conditions as the bones). Noreaming of the medullary canal is performed. A standardized closedfracture is produced 2 mm above the tibiofibular junction by three-pointbending using specially designed adjustable forceps with blunt jaws. Tominimize soft tissue damage, care is taken not to displace the fracture.The skin is closed with monofilament nylon sutures. The operation isperformed under sterile conditions. Radiographs of all fractures aretaken immediately after nailing, and rats with fractures outside thespecified diaphyseal area or with displaced nails are excluded. Theremaining animals are divided randomly into the following groups with10-12 animals per each subgroup per time point for testing the fracturehealing. The rats are administered on a daily basis per orally withvehicle or with a GPR119 agonist. The GPR119 agonist is used at anamount between 0.001 mg/kg body weight and 100 mg/kg body weight.Treatment is continued for 10, 20, 40 and 80 days.

At 10, 20, 40 and 80 days, 10-12 rats from each group are anesthetizedwith Ketamine and sacrificed by exsanguination. Both tibiofibular bonesare removed by dissection and all soft tissue is stripped. Bones from5-6 rats for each group are stored in 70% ethanol for histologicalanalysis, and bones from another 5-6 rats for each group are stored in abuffered Ringer's solution (+4° C., pH 7.4) for radiographs andbiomechanical testing which is performed.

Histological Analysis

The methods for histological analysis of fractured bone have beenpreviously published by Mosekilde and Bak (Bone (1993) 14:19-27).Briefly, the fracture site is sawed 8 mm to each side of the fractureline, embedded undecalcified in methymethacrylate, and cut frontalssections on a Reichert-Jung Polycut microtome in 8 μm thick.Masson-Trichome stained mid-frontal sections (including both tibia andfibula) are used for visualization of the cellular and tissue responseto fracture healing with and without treatment. Sirius red stainedsections are used to demonstrate the characteristics of the callusstructure and to differentiate between woven bone and lamellar bone atthe fracture site. The following measurements are performed: (1)fracture gap—measured as the shortest distance between the cortical boneends in the fracture, (2) callus length and callus diameter, (3) totalbone volume area of callus, (4) bony tissue per tissue area inside thecallus area, (5) fibrous tissue in the callus, and (6) cartilage area inthe callus.

Biomechanical Analysis

The methods for biomechanical analysis have been previously published byBak and Andreassen (Calcif Tissue Int (1989) 45:292-297). Briefly,radiographs of all fractures are taken prior to the biomechanical test.The mechanical properties of the healing fractures are analyzed by adestructive three- or four-point bending procedure. Maximum load,stiffness, energy at maximum load, deflection at maximum load, andmaximum stress are determined.

Example 5 Full-Length Cloning of Endogenous Human GPR119

Polynucleotide encoding endogenous human GPR119 was cloned by PCR usingthe GPR119 specific primers 5′-GTCCTGCCACTTCGAGACATGG-3′ (SEQ ID NO:3;sense, ATG as initiation codon) 5′-GAAACTTCTCTGCCCTTACCGTC-3′ (SEQ IDNO:4; antisense, 3′ of stop codon) and human genomic DNA as template.TaqPlus Precision™ DNA polymerase (Stratagene) was used foramplification by the following cycle with step 2 to step 4 repeated 35times: 94° C., 3 minutes; 94° C., 1 minute; 58° C., 1 minute; 72° C., 2minutes; 72° C., 10 minutes. A 1.0 Kb PCR fragment of predicted size wasisolated and cloned into the pCRII-TOPO™ vector (Invitrogen) andcompletely sequenced using the T7 DNA sequenase kit (Amersham). See, SEQID NO:1 for nucleic acid sequence and SEQ ID NO:2 for the deduced aminoacid sequence.

Example 6

Receptor Expression

Although a variety of cells are available to the art for the expressionof G protein-coupled receptors, it is most preferred that eukaryoticcells be utilized. In certain embodiments, mammalian cells ormelanophores are utilized. The following are illustrative; those ofordinary skill in the art are credited with the ability to determinethose techniques that are preferentially beneficial for the needs of theartisan. See, e.g., Example 9, infra, as it relates to melanophores.

a. Transient Transfection

On day one, 6×10⁶/10 cm dish of 293 cells are plated out. On day two,two reaction tubes are prepared (the proportions to follow for each tubeare per plate): tube A is prepared by mixing 4 μg DNA (e.g., pCMVvector; pCMV vector with receptor cDNA, etc.) in 0.5 ml serum free DMEM(Gibco BRL); tube B is prepared by mixing 24 μl lipofectamine (GibcoBRL) in 0.5 ml serum free DMEM. Tubes A and B are admixed by inversions(several times), followed by incubation at room temperature for 30-45min. The admixture is referred to as the “transfection mixture”. Plated293 cells are washed with 1×PBS, followed by addition of 5 ml serum freeDMEM. 1 ml of the transfection mixture is added to the cells, followedby incubation for 4 hrs at 37° C./5% CO₂. The transfection mixture isremoved by aspiration, followed by the addition of 10 ml of DMEM/10%Fetal Bovine Serum. Cells are incubated at 37° C./5% CO₂. After 48 hrincubation, cells are harvested and utilized for analysis.

b. Stable Cell Lines

Approximately 12×10⁶ 293 cells are plated on a 15 cm tissue cultureplate. Grown in DME High Glucose Medium containing ten percent fetalbovine serum and one percent sodium pyruvate, L-glutamine, andantibiotics. Twenty-four hours following plating of 293 cells (or to±80% confluency), the cells are transfected using 12 μg of DNA (e.g.,pCMV-neo^(r) vector with receptor cDNA). The 12 μg of DNA is combinedwith 60 μl of lipofectamine and 2 ml of DME High Glucose Medium withoutserum. The medium is aspirated from the plates and the cells are washedonce with medium without serum. The DNA, lipofectamine, and mediummixture are added to the plate along with 10 ml of medium without serum.Following incubation at 37° C. for four to five hours, the medium isaspirated and 25 ml of medium containing serum is added. Twenty-fourhours following transfection, the medium is aspirated again, and freshmedium with serum is added. Forty-eight hours following transfection,the medium is aspirated and medium with serum is added containinggeneticin (G418 drug) at a final concentration of approximately 12×10⁶293 cells are plated on a 15 cm tissue culture plate. Grown in DME HighGlucose Medium containing ten percent fetal bovine serum and one percentsodium pyruvate, L-glutamine, and antibiotics. Twenty-four hoursfollowing plating of 293 cells (or to ˜80% confluency), the cells aretransfected using 12 μg of DNA (e.g., pCMV vector with receptor cDNA).The 12 μg of DNA is combined with 60 μl of lipofectamine and 2 ml of DMEHigh Glucose Medium without serum. The medium is aspirated from theplates and the cells are washed once with medium without serum. The DNA,lipofectamine, and medium mixture are added to the plate along with 10ml of medium without serum. Following incubation at 37° C. for four tofive hours, the medium is aspirated and 25 ml of medium containing serumis added. Twenty-four hours following transfection, the medium isaspirated again, and fresh medium with serum is added. Forty-eight hoursfollowing transfection, the medium is aspirated and medium with serum isadded containing geneticin (G418 drug) at a final concentration of 500μg/ml. The transfected cells now undergo selection for positivelytransfected cells containing the G418 resistance gene. The medium isreplaced every four to five days as selection occurs. During selection,cells are grown to create stable pools, or split for stable clonalselection.

Example 7 Assays for Screening Candidate Compounds as, e.g., GPR119Agonists

A variety of approaches are available for screening candidate compoundsas, e.g., GPR119 agonists. The following are illustrative; those ofordinary skill in the art are credited with the ability to determinethose techniques that are preferentially beneficial for the needs of theartisan. Assays for screening compounds as agonists of a Gprotein-coupled receptor are well known to the skilled artisan (see,e.g., international Application WO 02/42461).

1. Membrane Binding Assays: [³⁵S]GTPγS Assay

When a G protein-coupled receptor is in its active state, either as aresult of ligand binding or constitutive activation, the receptorcouples to a G protein and stimulates the release of GDP and subsequentbinding of GTP to the G protein. The alpha subunit of the Gprotein-receptor complex acts as a GTPase and slowly hydrolyzes the GTPto GDP, at which point the receptor normally is deactivated. Activatedreceptors continue to exchange GDP for GTP. The non-hydrolyzable GTPanalog, [³⁵S]GTPγS, can be utilized to demonstrate enhanced binding of[³⁵S]GTPγS to membranes expressing activated receptors. The advantage ofusing [³⁵S]GTPγS binding to measure activation is that: (a) it isgenerically applicable to all G protein-coupled receptors; (b) it isproximal at the membrane surface making it less likely to pick-upmolecules which affect the intracellular cascade.

The assay utilizes the ability of G protein coupled receptors tostimulate [³⁵S]GTPγS binding to membranes expressing the relevantreceptors. The assay is generic and has application to drug discovery atall G protein-coupled receptors.

Membrane Preparation

In some embodiments, membranes comprising a G protein-coupled receptorof the invention and for use in the identification of candidatecompounds as, e.g., agonists of the receptor, are preferably prepared asfollows:

a. Materials

“Membrane Scrape Buffer” is comprised of 20 mM HEPES and 10 mM EDTA, pH7.4; “Membrane Wash Buffer” is comprised of 20 mM HEPES and 0.1 mM EDTA,pH 7.4; “Binding Buffer” is comprised of 20 mM HEPES, 100 mM NaCl, and10 mM MgCl₂, pH 7.4.

b. Procedure

All materials will be kept on ice throughout the procedure. Firstly, themedia will be aspirated from a confluent monolayer of cells, followed byrinse with 10 ml cold PBS, followed by aspiration. Thereafter, 5 ml ofMembrane Scrape Buffer will be added to scrape cells; this will befollowed by transfer of cellular extract into 50 ml centrifuge tubes(centrifuged at 20,000 rpm for 17 minutes at 4° C.). Thereafter, thesupernatant will be aspirated and the pellet will be resuspended in 30ml Membrane Wash Buffer followed by centrifuge at 20,000 rpm for 17minutes at 4° C. The supernatant will then be aspirated and the pelletresuspended in Binding Buffer. This wilt then be homogenized using aBrinkman Polytron™ homogenizer (15-20 second bursts until the allmaterial is in suspension). This is referred to herein as “MembraneProtein”.

Bradford Protein Assay

Following the homogenization, protein concentration of the membraneswill be determined using the Bradford Protein Assay (protein can bediluted to about 1.5 mg/ml, aliquoted and frozen (−80° C.) for lateruse; when frozen, protocol for use will be as follows: on the day of theassay, frozen Membrane Protein is thawed at room temperature, followedby vortex and then homogenized with a Polytron at about 12×1,000 rpm forabout 5-10 seconds; it is noted that for multiple preparations, thehomogenizer should be thoroughly cleaned between homogenization ofdifferent preparations).

a. Materials

Binding Buffer (as per above); Bradford Dye Reagent; Bradford ProteinStandard will be utilized, following manufacturer instructions (Biorad,cat. no. 500-0006).

b. Procedure

Duplicate tubes will be prepared, one including the membrane, and one asa control “blank”. Each contained 800 μl Binding Buffer. Thereafter, 10μl of Bradford Protein Standard (1 mg/ml) will be added to each tube,and 10 μl of membrane Protein will then be added to just one tube (notthe blank). Thereafter, 200 μl of Bradford Dye Reagent will be added toeach tube, followed by vortex of each. After five (5) minutes, the tubeswill be re-vortexed and the material therein will be transferred tocuvettes. The cuvettes will then be read using a CECIL 3041spectrophotometer, at wavelength 595.

Identification Assay

a. Materials

GDP Buffer consists of 37.5 ml Binding Buffer and 2 mg GDP (Sigma, cat.no. G-7127), followed by a series of dilutions in Binding Buffer toobtain 0.2 μM GDP (final concentration of GDP in each well was 0.1 μMGDP); each well comprising a candidate compound, has a final volume of200 μl consisting of 100 μl GDP Buffer (final concentration, 0.1 μMGDP), 50 μl Membrane Protein in Binding Buffer, and 50 μl [³⁵S]GTPγS(0.6 nM) in Binding Buffer (2.5 μl [³⁵S]GTPγS per 10 ml Binding Buffer).

b. Procedure

Candidate compounds will be preferably screened using a 96-well plateformat (these can be frozen at −80° C.). Membrane Protein (or membraneswith expression vector excluding the Target GPCR, as control), will behomogenized briefly until in suspension. Protein concentration will thenbe determined using the Bradford Protein Assay set forth above. MembraneProtein (and control) will then be diluted to 0.25 mg/ml in BindingBuffer (final assay concentration, 12.5 μg/well). Thereafter, 100 μl GDPBuffer was added to each well of a Wallac Scintistrip™ (Wallac). A 5 ulpin-tool will then be used to transfer 5 μl of a candidate compound intosuch well (i.e., 5 μl in total assay volume of 200 μl is a 1:40 ratiosuch that the final screening concentration of the candidate compound is10 μM). Again, to avoid contamination, after each transfer step the pintool should be rinsed in three reservoirs comprising water (1×), ethanol(1×) and water (2×)—excess liquid should be shaken from the tool aftereach rinse and dried with paper and kimwipes. Thereafter, 50 μl ofMembrane Protein will be added to each well (a control well comprisingmembranes without the Target GPCR was also utilized), and pre-incubatedfor 5-10 minutes at room temperature. Thereafter, 50 μl of [³⁵S]GTPγS(0.6 nM) in Binding Buffer will be added to each well, followed byincubation on a shaker for 60 minutes at room temperature (again, inthis example, plates were covered with foil). The assay will then bestopped by spinning of the plates at 4000 RPM for 15 minutes at 22° C.The plates will then be aspirated with an 8 channel manifold and sealedwith plate covers. The plates will then be read on a Wallac 1450 usingsetting “Prot. #37” (as per manufacturer's instructions).

2. Adenylyl Cyclase Assay

A Flash Plate™ Adenylyl Cyclase kit (New England Nuclear; Cat. No.SMP004A) designed for cell-based assays can be modified for use withcrude plasma membranes. The Flash Plate wells can contain a scintillantcoating which also contains a specific antibody recognizing cAMP. ThecAMP generated in the wells can be quantitated by a direct competitionfor binding of radioactive cAMP tracer to the cAMP antibody. Thefollowing serves as a brief protocol for the measurement of changes incAMP levels in cells that express the receptors.

In certain embodiments, a modified Flash Plate™ Adenylyl Cyclase kit(New England Nuclear; Cat. No. SMP004A) is utilized for identificationof candidate compounds as, e.g., GPR119 agonists in accordance with thefollowing protocol.

Cells transfected with a G protein-coupled receptor of the invention areharvested approximately three days after transfection. Membranes areprepared by homogenization of suspended cells in buffer containing 20 mMHEPES, pH 7.4 and 10 mM MgCl₂. Homogenization is performed on ice usinga Brinkman Polytron™ for approximately 10 seconds. The resultinghomogenate is centrifuged at 49,000×g for 15 minutes at 4° C. Theresulting pellet is then resuspended in buffer containing 20 mM HEPES,pH 7.4 and 0.1 mM EDTA, homogenized for 10 seconds, followed bycentrifugation at 49,000×g for 15 minutes at 4° C. The resulting pelletis then stored at −80° C. until utilized. On the day of directidentification screening, the membrane pellet is slowly thawed at roomtemperature, resuspended in buffer containing 20 mM HEPES, pH 7.4 and 10mM MgCl₂, to yield a final protein concentration of 0.60 mg/ml (theresuspended membranes are placed on ice until use).

cAMP standards and Detection Buffer (comprising 2 μCi of tracer([¹²⁵I]cAMP (100 μl) to 11 ml Detection Buffer)) are prepared andmaintained in accordance with the manufacturer's instructions. AssayBuffer was prepared fresh for screening and contained 20 mM HEPES, pH7.4, 10 mM MgCl₂, 20 mM phosphocreatine (Sigma), 0.1 units/ml creatinephosphokinase (Sigma), 50 μM GTP (Sigma), and 0.2 mM ATP (Sigma); AssayBuffer was then stored on ice until utilized.

Candidate compounds are added, preferably, to e.g. 96-well plate wells(3 μl/well; 12 μM final assay concentration), together with 40 μlMembrane Protein (30 μg/well) and 50 μl of Assay Buffer. This admixturewas then incubated for 30 minutes at room temperature, with gentleshaking.

Following the incubation, 100 μl of Detection Buffer is added to eachwell, followed by incubation for 2-24 hours. Plates are then counted ina Wallac MicroBeta™ plate reader using “Prot. #31” (as permanufacturer's instructions).

3. CRE-Luc Reporter Assay

293 and 293T cells are plated-out on 96 well plates at a density of2×10⁴ cells per well and were transfected using Lipofectamine Reagent(BRL) the following day according to manufacturer instructions. ADNA/lipid mixture is prepared for each 6-well transfection as follows:260 ng of plasmid DNA in 100 μl of DMEM is gently mixed with 2 μl oflipid in 100 μl of DMEM (the 260 ng of plasmid DNA consists of 200 ng ofa 8xCRE-Luc reporter plasmid, 50 ng of pCMV comprising a Gprotein-coupled receptor of the invention or pCMV alone, and 10 ng of aGPRS expression plasmid (GPRS in pcDNA3 (Invitrogen)). The 8XCRE-Lucreporter plasmid was prepared as follows: vector SRIF-β-gal was obtainedby cloning the rat somatostatin promoter (−71/+51) at BgIV-HindIII sitein the pβgal-Basic Vector (Clontech). Eight (8) copies of cAMP responseelement were obtained by PCR from an adenovirus template AdpCF126CCRE8[see, Suzuki et al., Hum Gene Ther (1996) 7:1883-1893; the disclosure ofwhich is herein incorporated by reference in its entirety) and clonedinto the SRIF-β-gal vector at the Kpn-BgIV site, resulting in the8xCRE-β-gal reporter vector. The 8xCRE-Luc reporter plasmid wasgenerated by replacing the beta-galactosidase gene in the 8xCRE-β-galreporter vector with the luciferase gene obtained from the pGL3-basicvector (Promega) at the HindIII-BamHI site. Following 30 min. incubationat room temperature, the DNA/lipid mixture is diluted with 400 μl ofDMEM and 100 μl of the diluted mixture is added to each well. 100 μl ofDMEM with 10% FCS are added to each well after a 4 hr incubation in acell culture incubator. The following day the transfected cells arechanged with 200 μl/well of DMEM with 10% FCS. Eight (8) hours later,the wells are changed to 100 μl/well of DMEM without phenol red, afterone wash with PBS. Luciferase activity is measured the next day usingthe LucLite™ reporter gene assay kit (Packard) following manufacturerinstructions and read on a 1450 MicroBeta™ scintillation andluminescence counter (Wallac).

Example 8 Whole Cell Adenylyl Cyclase Assay for, e.g., GPR119 AgonistActivity

Cyclic AMP measurements are done with a Flash Plate™ Adenylyl Cyclasekit (New England Nuclear) according to the supplier's protocol. HEK293cells are plated in 15-cm tissue culture dish at 12×10⁶ cells per dishin regular growth medium (DMEM/10% FBS). On the next day, 10 μg ofeither empty vector DNA or expression plasmid DNA are transfected intocells with lipofectamine (Invitrogen, Carlsbad, Calif.) according tomanufacturer's protocol. After 24 hours in culture, transfected cellsare harvested in GIBCO cell dissociation buffer (Cat #13151-014),pelleted by centrifugation for 5 minutes at 1,100 rpm, and carefullyre-suspended into an appropriate volume of Assay Buffer (50% 1×PBS and50% Stimulation Buffer) to give a final cell count at 2×10⁶ cells/ml.Test compounds are prepared in 50 μl Assay Buffer at desired assayconcentration where indicated, and pipetted into wells of the 96-wellFlash Plate. The cell suspension prepared above was then added (50 μlper well). After an incubation time of 60 minutes at room temperature,100 μl of Detection Mix containing tracer [¹²⁵I]-cAMP is then added tothe wells. Plates are incubated for additional 2 hours followed bycounting in a Wallac MicroBeta scintillation counter. Values ofcAMP/well are extrapolated from a standard cAMP curve which is includedon each assay plate.

An increase in cAMP level in GPR119-transfected HEK293 cells over thatin HEK293 cells transfected with empty vector is indicative of a testcompound being a compound that stimulates GPR119 receptor functionality.

Example 9 Melanophore Assay for, e.g., GPR119 Agonist Activity

Melanophores are maintained in culture as reported by Potenza et al[Pigment Cell Research (1992) 5:372-378] and transfected with anexpression vector encoding a GPR119 receptor (GPR119; e.g., humanGPR119, GenBank® Accession No. AAP72125 and alleles thereof) usingelectroporation. Following electroporation, the transfected cells areplated into 96 well plates for the assay. The cells are then allowed togrow for 48 hours in order to both recover from the electroporationprocedure and attain maximal receptor expression levels.

On the assay day, the growth medium on the cells is replaced withserum-free buffer containing 10 nM melatonin. The melatonin acts via anendogenous Gi-coupled GPCR in the melanophores to lower intracellularcAMP levels. In response to lowered cAMP levels, the melanophorestranslocate their pigment to the center of the cell. The net effect ofthis is a significant decrease in the absorbance reading of the cellmonolayer in the well, measured at 600-650 nM.

After a 1-hour incubation in melatonin, the cells become completelypigment-aggregated. At this point a baseline absorbance reading iscollected. Serial dilutions of test compounds are then added to theplate, and compounds having GPR119 agonist activity produce increases inintracellular cAMP levels. In response to these increased cAMP levels,the melanophores translocate their pigment back into the cell periphery.After one hour, stimulated cells are fully pigment-dispersed. The cellmonolayer in the dispersed state absorbs much more light in the 600-650nm range. The measured increase in absorbance compared to the baselinereading allows one to quantitate the degree of receptor stimulation andplot a dose-response curve.

Materials and methods relating to melanophore assay are found in U.S.Pat. Nos. 5,462,856 and 6,051,386, the disclosure of each of which isherein incorporated by reference in its entirety.

An increase in pigment dispersion in GPR119-transfected melanophoresover over that in melanophores transfected with empty vector isindicative of a test compound being a compound that stimulates GPR119receptor functionality.

Other assays for identifying a compound as a GPR119 agonist will bereadily apparent to the skilled artisan (see, e.g., Example 7, supra).

Example 10 Yeast Reporter Assay for, e.g., GPR119 Agonist Activity

The yeast cell-based reporter assays have previously been described inthe literature (e.g., see Miret et al, J Biol Chem (2002) 277:6881-6887;Campbell et al, Bioorg Med Chem Lett (1999) 9:2413-2418; King et al,Science (1990) 250:121-123; WO 99/14344; WO 00/12704; and U.S. Pat. No.6,100,042). Briefly, yeast cells have been engineered such that theendogenous yeast G-alpha (GPA1) has been deleted and replaced withG-protein chimeras constructed using multiple techniques. Additionally,the endogenous yeast alpha-cell GPCR, Step 3 has been deleted to allowfor a homologous expression of a mammalian GPCR of choice. In the yeast,elements of the pheromone signaling transduction pathway, which areconserved in eukaryotic cells (for example, the mitogen-activatedprotein kinase pathway), drive the expression of Fus1. By placingβ-galactosidase (LacZ) under the control of the Fus1 promoter (Fus1p), asystem has been developed whereby receptor activation leads to anenzymatic readout.

Yeast cells are transformed by an adaptation of the lithium acetatemethod described by Agatep et al (Agatep et al, 1998, Transformation ofSaccharomyces cerevisiae by the lithium acetate/single-stranded carrierDNA/polyethylene glycol (LiAc/ss-DNA/PEG) protocol. Technical TipsOnline, Trends Journals, Elsevier). Briefly, yeast cells are grownovernight on yeast tryptone plates (YT). Carrier single-stranded DNA (10μg), 2 μg of each of two Fus1p-LacZ reporter plasmids (one with URAselection marker and one with TRP), 2 μg of GPR119 (e.g., humanreceptor) in yeast expression vector (2 μg origin of replication) and alithium acetate/polyethylene glycol/TE buffer is pipetted into anEppendorf tube. The yeast expression plasmid containing the receptor/noreceptor control has a LEU marker. Yeast cells are inoculated into thismixture and the reaction proceeds at 30° C. for 60 min. The yeast cellsare then heat-shocked at 42° C. for 15 min. The cells are then washedand spread on selection plates. The selection plates are syntheticdefined yeast media minus LEU, URA and TRP (SD-LUT). After incubating at30° C. for 2-3 days, colonies that grow on the selection plates are thentested in the LacZ assay.

In order to perform fluorimetric enzyme assays for β-galactosidase,yeast cells carrying the subject GPR119 receptor are grown overnight inliquid SD-LUT medium to an unsaturated concentration (i.e. the cells arestill dividing and have not yet reached stationary phase). They arediluted in fresh medium to an optimal assay concentration and 90 μl ofyeast cells are added to 96-well black polystyrene plates (Costar). Testcompounds, dissolved in DMSO and diluted in a 10% DMSO solution to 10×concentration, are added to the plates and the plates placed at 30° C.for 4 h. After 4 h, the substrate for the β-galactosidase is added toeach well. In these experiments, Fluorescein di (β-D-galactopyranoside)is used (FDG), a substrate for the enzyme that releases fluorescein,allowing a fluorimetric read-out. 20 μl per well of 500 μM FDG/2.5%Triton X100 is added (the detergent is necessary to render the cellspermeable). After incubation of the cells with the substrate for 60 min,20 μl per well of 1 M sodium carbonate is added to terminate thereaction and enhance the fluorescent signal. The plates are then read ina fluorimeter at 485/535 nm.

An increase in fluorescent signal in GPR119-transformed yeast cells overthat in yeast cells transformed with empty vector is indicative of atest compound being a compound that stimulates GPR119 receptorfunctionality (e.g., a compound that is an agonist or partial agonist ofGPR119). In certain embodiments, compounds of the invention give anincrease in fluorescent signal above that of the background signal (thesignal obtained in the presence of vehicle alone).

Example 11 Radiolabeled Compound

In certain embodiments, a compound known to be a ligand of a Gprotein-coupled receptor of the invention is radiolabeled. Aradiolabeled compound as described herein can be used in a screeningassay to identify/evaluate compounds. In general terms, a newlysynthesized or identified compound (i.e., test compound) can beevaluated for its ability to reduce binding of the radiolabeled knownligand to the receptor, by its ability to reduce formation of thecomplex between the radiolabeled known ligand and the receptor. Suitableradionuclides that may be incorporated in compounds of the presentinvention include but are not limited to ³H (also written as T), ¹¹C,¹⁴C, ¹⁸F, ¹²⁵I, ⁸²Br, ¹²³I, ¹²⁴I, ¹²⁵I, ¹³¹I, ⁷⁵Br, ⁷⁶Br, ¹⁵O, ¹³N, ³⁵Sand ⁷⁷Br. Compounds that incorporate ³H, ¹⁴C, ¹²⁵I, ¹³¹I, ³⁵S or ⁸²Brwill generally be most useful.

It is understood that a “radiolabelled” compound” is a compound that hasincorporated at least one radionuclide. In some embodiments, theradionuclide is selected from the group consisting of ³H, ¹⁴C, ¹²⁵I, ³⁵Sand ⁸²Br. In some embodiments, the radionuclide ³H or ¹⁴C. Moreover, itshould be understood that all of the atoms represented in the compoundsknown to be ligands of a G protein-coupled receptor of the invention canbe either the most commonly occurring isotope of such atoms or the morescarce radioisotope or nonradioactive isotope.

Synthetic methods for incorporating radioisotopes into organic compoundsincluding those applicable to those compounds known to be ligands of a Gprotein-coupled receptor of the invention are well known in the art andinclude incorporating activity levels of tritium into target moleculesinclude: A. Catalytic Reduction with Tritium Gas—This procedure normallyyields high specific activity products and requires halogenated orunsaturated precursors. B. Reduction with Sodium Borohydride [³H]—Thisprocedure is rather inexpensive and requires precursors containingreducible functional groups such as aldehydes, ketones, lactones,esters, and the like. C. Reduction with Lithium Aluminum Hydride[³H]—This procedure offers products at almost theoretical specificactivities. It also requires precursors containing reducible functionalgroups such as aldehydes, ketones, lactones, esters, and the like. D.Tritium Gas Exposure Labeling—This procedure involves exposingprecursors containing exchangeable protons to tritium gas in thepresence of a suitable catalyst. E. N-Methylation using Methyl Iodide[³H]—This procedure is usually employed to prepare O-methyl or N-methyl(3H) products by treating appropriate precursors with high specificactivity methyl iodide (3H). This method in general allows for highspecific activity, such as about 80-87 Ci/mmol.

Synthetic methods for incorporating activity levels of ¹²⁵I into targetmolecules include: A. Sandmeyer and like reactions—This proceduretransforms an aryl or heteroaryl amine into a diazonium salt, such as atetrafluoroborate salt, and subsequently to ¹²⁵I labelled compound usingNa¹²⁵I. A represented procedure was reported by Zhu, D.-G. andco-workers in J. Org. Chem. 2002, 67, 943-948. B. Ortho ¹²⁵Iodination ofphenols—This procedure allows for the incorporation of ¹²⁵I at the orthoposition of a phenol as reported by Collier, T. L. and co-workers in J.Labelled Compd Radiopharm. 1999, 42, S264-S266. C. Aryl and heteroarylbromide exchange with ¹²⁵I—This method is generally a two step process.The first step is the conversion of the aryl or heteroaryl bromide tothe corresponding tri-alkyltin intermediate using for example, a Pdcatalyzed reaction (i.e. Pd(Ph₃P)₄] or through an aryl or heteroaryllithium, in the presence of a tri-alkyltinhalide or hexaalkylditin[e.g., (CH₃)₃SnSn(CH₃)₃). A represented procedure was reported by Bas,M.-D. and co-workers in J. Labelled Compd Radiopharm. 2001, 44,S280-S282.

The foregoing techniques are intended to be illustrative and notlimiting. Other techniques for radiolabeling a compound known to be aligand of a G protein-coupled receptor of the invention are well knownto the skilled artisan.

Example 12 Receptor Binding Assay

A test compound can be evaluated for its ability to reduce formation ofthe complex between a compound known to be a ligand of a Gprotein-coupled receptor of the invention and the receptor. In certainembodiments, the known ligand is radiolabeled. The radiolabeled knownligand can be used in a screening assay to identify/evaluate compounds.In general terms, a newly synthesized or identified compound (i.e., testcompound) can be evaluated for its ability to reduce binding of theradiolabeled known ligand to the receptor, by its ability to reduceformation of the complex between the radiolabeled known ligand and thereceptor.

A level of specific binding of the radiolabled known ligand in thepresence of the test compound less than a level of specific binding ofthe radiolabeled known ligand in the absence of the test compound isindicative of less of the complex between said radiolabeled known ligandand said receptor being formed in the presence of the test compound thanin the absence of the test compound.

Assay Protocol for Detecting the Complex Between a Compound Known to bea Ligand of a G Protein-Coupled Receptor of the Invention and theReceptor

A. Preparation of the Receptor

293 cells are transiently transfected with 10 ug expression vectorcomprising a polynucleotide encoding a G protein-coupled receptor of theinvention using 60 ul Lipofectamine (per 15-cm dish). The transientlytransfected cells are grown in the dish for 24 hours (75% confluency)with a media change and removed with 10 ml/dish of Hepes-EDTA buffer (20mM Hepes+10 mM EDTA, pH 7.4). The cells are then centrifuged in aBeckman Coulter centrifuge for 20 minutes, 17,000 rpm (JA-25.50 rotor).Subsequently, the pellet is resuspended in 20 mM Hepes+1 mM EDTA, pH 7.4and homogenized with a 50-ml Dounce homogenizer and again centrifuged.After removing the supernatant, the pellets are stored at −80° C., untilused in binding assay. When used in the assay, membranes are thawed onice for 20 minutes and then 10 mL of incubation buffer (20 mM Hepes, 1mM MgCl₂, 100 mM NaCl, pH 7.4) added. The membranes are then vortexed toresuspend the crude membrane pellet and homogenized with a BrinkmannPT-3100 Polytron homogenizer for 15 seconds at setting 6. Theconcentration of membrane protein is determined using the BRL Bradfordprotein assay.

B. Binding Assay

For total binding, a total volume of 50 ul of appropriately dilutedmembranes (diluted in assay buffer containing 50 mM Tris HCl (pH 7.4),10 mM MgCl₂, and 1 mM EDTA; 5-50 ug protein) is added to 96-wellpolyproylene microtiter plates followed by addition of 100 ul of assaybuffer and 50 ul of a radiolabeled known ligand. For nonspecificbinding, 50 ul of assay buffer is added instead of 100 ul and anadditional 50 ul of 10 uM said known ligand which is not radiolabeled isadded before 50 ul of said radiolabeled known ligand is added. Platesare then incubated at room temperature for 60-120 minutes. The bindingreaction is terminated by filtering assay plates through a MicroplateDevices GF/C Unifilter filtration plate with a Brandell 96-well plateharvestor followed by washing with cold 50 mM Tris HCl, pH 7.4containing 0.9% NaCl. Then, the bottom of the filtration plate aresealed, 50 ul of Optiphase Supermix is added to each well, the top ofthe plates are sealed, and plates are counted in a Trilux MicroBetascintillation counter. For determining whether less of the complexbetween said radiolabeled known ligand and said receptor is formed inthe presence of a test compound, instead of adding 100 ul of assaybuffer, 100 ul of appropriately diluted said test compound is added toappropriate wells followed by addition of 50 ul of said radiolabledknown ligand.

C. Calculations

The test compounds are initially assayed at 10, 1 and 0.1 μm and then ata range of concentrations chosen such that the middle dose would causeabout 50% inhibition of binding of the radiolabeled known ligand (i.e.,IC₅₀). Specific binding in the absence of test compound (B_(O)) is thedifference of total binding (B_(T)) minus non-specific binding (NSB) andsimilarly specific binding (in the presence of test compound) (B) is thedifference of displacement binding (B_(D)) minus non-specific binding(NSB). IC₅₀ is determined from an inhibition response curve, logit-logplot of % B/B_(O) vs concentration of test compound.

K_(i) is calculated by the Cheng and Prustoff transformation:

K _(i) =IC ₅₀/(1+[L]/K _(D))

where [L] is the concentration of radiolabled known ligand used in theassay and K_(D) is the dissociation constant of the radiolabeled knownligand determined independently under the same binding conditions.

Example 13 Effect OF GPR119 Agonist on GIP Secretion in EnteroendocrineCell Line or in Cells in Tissue Derived from a K Cell Rich Region ofSmall Intestine

A GPR119 agonist in accordance with the present invention can be shownto stimulate GIP secretion in an enteroendocrine cell line or in cellsin tissue derived from a K cell rich region of small intestine [e.g.,duodenum or jejunum tissue; see, e.g., Sondhi et al, Pharmacogenetics J(2006) 6:131-140] using the in vitro assay described here.Enteroendocrine cells or cells in tissue derived from a K cell richregion of small intestine are plated in 24-well plates on day one incomplete culture medium (DMEM/10% FBS). On day two the culture medium isreplaced with a low glucose medium (DMEM/3 mM Glucose/10% FBS). On daythree cells are washed twice with 1×PBS. The washed cells are stimulatedwith vehicle or with GPR119 agonist at various concentrations (e.g., inthe range of 1 nM to 20 uM) or with forskolin (1 uM) as a positivecontrol in serum free DMEM with 15 mM glucose for one hour at 37° C. and5% CO₂ in a tissue culture incubator. The supernatants are thencollected and clarified by centrifugation at 500 g and 4° C. for 5minutes. GIP released into the supernatant is determined by ELISA usingreagents purchased from LINCO Research Laboratory [Rat/Mouse GastricInhibitory Polypeptide (Total) ELISA Catalog #EZRMGIP-55K], followinginstructions provided by the supplier.

While the foregoing specification teaches the principles of the presentinvention, with examples provided for the purpose of illustration, itwill be understood that the practice of the invention encompasses all ofthe usual variations, adaptions, or modifications, as come within thescope of the following claims and its equivalents.

1. A method for identifying GIP secretagogues, compounds useful forpreventing or treating a condition characterized by low bone mass, orcompounds useful for increasing bone mass in an individual, comprisingthe steps of: (a) contacting a test compound with a host cell or withmembrane of a host cell comprising a G protein-coupled receptor, whereinthe G protein-coupled receptor comprises an amino acid sequence selectedfrom the group consisting of: (i) amino acids 1-335 of SEQ ID NO:2; (ii)amino acids 2-335 of SEQ ID NO:2; (iii) amino acids 2-335 of SEQ IDNO:2, with the proviso that the receptor does not comprise the aminoacid sequence of SEQ ID NO:2; (iv) the amino acid sequence of a Gprotein-coupled receptor encoded by a polynucleotide that is amplifiableby polymerase chain reaction (PCR) on a human DNA sample using specificprimers SEQ ID NO:3 and SEQ ID NO:4; (v) the amino acid sequence of a Gprotein-coupled receptor encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO:1; (vi) avariant of SEQ ID NO: 2; (vii) the amino acid sequence of (vi) whenselected from the group consisting of: (a′) the amino acid sequence of aG protein-coupled receptor having at least about 80% identity to SEQ IDNO: 2; and (b′) the amino acid sequence of a G protein-coupled receptorcomprising at least 20 contiguous amino acids of SEQ ID NO: 2; (viii)the amino acid sequence of a constitutively active version of a Gprotein-coupled receptor having SEQ ID NO: 2; and (ix) a biologicallyactive fragment of any one of (i) to (viii); and (b) determining theability of the test compound to stimulate functionality of the receptor;wherein the ability of the test compound to stimulate functionality ofthe receptor is indicative of the test compound being a GIPsecretagogue, a compound useful for treating or preventing a conditioncharacterized by low bone mass, or a compound useful for increasing bonemass in an individual.
 2. A method for identifying GIP secretagogues,compounds useful for preventing or treating a condition characterized bylow bone mass, or compounds useful for increasing bone mass in anindividual, comprising the steps of the method of claim 1, and furthercomprising: (c) contacting a compound which stimulates functionality ofthe receptor in step (b) in vitro with a vertebrate enteroendocrine cellor a cell capable of secreting GIP; and (d) determining whether thecompound stimulates GIP secretion from the vertebrate enteroendocrinecell or the cell capable of secreting GIP; wherein the ability of thetest compound to stimulate GIP secretion from the vertebrateenteroendocrine cell or cell capable of secreting GIP is indicative ofthe test compound being a GIP secretagogue, a compound useful fortreating or preventing a condition characterized by low bone mass, or acompound useful for increasing bone mass in an individual.
 3. A methodfor identifying GIP secretagogues, compounds useful for preventing ortreating a condition characterized by low bone mass, or compounds usefulfor increasing bone mass in an individual, comprising the steps of themethod of claim 1, and further comprising: (c) administering a compoundwhich stimulates functionality of the receptor in step (b) to avertebrate; and (d) determining whether the compound increases a GIPlevel in the vertebrate; wherein the ability of the test compound toincrease a GIP level in the vertebrate is indicative of the testcompound being a GIP secretagogue, a compound useful for treating orpreventing a condition characterized by low bone mass, or a compounduseful for increasing bone mass in an individual.
 4. A method inaccordance with claim 3, wherein the vertebrate is a non-humanvertebrate.
 5. A method for identifying compounds useful for preventingor treating a condition characterized by low bone mass or compoundsuseful for increasing bone mass in an individual, comprising the stepsof the method of claim 1, and further comprising: (c) administering acompound which stimulates functionality of the receptor in step (b) to avertebrate; and (d) determining whether the compound increases a levelof bone mass in the vertebrate; wherein the ability of the test compoundto increase a level of bone mass in the vertebrate is indicative of thetest compound being a compound useful for treating or preventing acondition characterized by low bone mass or a compound useful forincreasing bone mass in an individual.
 6. The method of claim 5, whereinthe vertebrate is a non-human vertebrate.
 7. The method of claim 1,wherein the receptor is recombinant.
 8. The method of claim 1, whereinthe host cell comprises an expression vector, said expression vectorcomprising a polynucleotide encoding the G protein-coupled receptor. 9.The method of claim 1, wherein said determining is through themeasurement of the level of a second messenger.
 10. The method of claim9, wherein the second messenger is selected from the group consisting ofcyclic AMP (cAMP), cyclic GMP (cGMP), inositol 1,4,5-triphosphate (IP₃),diacylglycerol (DAG), MAP kinase activity, MAPK/ERK kinase kinase-1(MEKK1) activity, and Ca²⁺.
 11. The method of claim 10, wherein a levelof cAMP is increased.
 12. The method of claim 1, wherein saiddetermining is through the use of a Melanophore assay, through themeasurement of GTPγS binding to a membrane comprising said GPCR, orthrough a reporter assay.
 13. A method in accordance with claim 1,wherein the host cell is a mammalian host cell.
 14. A method inaccordance with claim 1, wherein the host cell is a yeast host cell. 15.A method in accordance with claim 1, wherein the host cell is amelanophore host cell.
 16. The method of claim 1, wherein the testcompound is a small molecule.
 17. The method of claim 1, wherein thereceptor comprises the amino acid sequence of a G protein-coupledreceptor having at least about 80% identity to SEQ ID NO:
 2. 18. Themethod of claim 1, wherein the receptor comprises the amino acidsequence of SEQ ID NO:
 2. 19.-24. (canceled)
 25. A method foridentifying GIP secretagogues, compounds useful for preventing ortreating a condition characterized by low bone mass, or compounds usefulfor increasing bone mass in an individual, comprising the steps of: (a)contacting a GPR119 agonist in vitro with a vertebrate enteroendocrinecell or a cell capable of secreting GIP; and (b) determining whether theGPR119 agonist stimulates GIP secretion from the vertebrateenteroendocrine cell or the cell capable of secreting GIP; wherein theability of the GPR119 agonist to stimulate GIP secretion from thevertebrate enteroendocrine cell or cell capable of secreting GIP isindicative of the GPR119 agonist being a GIP secretagogue, a compounduseful for treating or preventing a condition characterized by low bonemass, or a compound useful for increasing bone mass in an individual.26. A method for identifying GIP secretagogues, compounds useful forpreventing or treating a condition characterized by low bone mass, orcompounds useful for increasing bone mass in an individual, comprisingthe steps of: (a) administering a GPR119 agonist to a vertebrate; and(b) determining whether the GPR119 agonist increases a GIP level in thevertebrate; wherein the ability of the GPR119 agonist to increase a GIPlevel in the vertebrate is indicative of the GPR119 agonist being a GIPsecretagogue, a compound useful for treating or preventing a conditioncharacterized by low bone mass, or a compound useful for increasing bonemass in an individual.
 27. A method in accordance with claim 26, whereinthe vertebrate is a non-human vertebrate.
 28. A method for identifyingcompounds useful for preventing or treating a condition characterized bylow bone mass or compounds useful for increasing bone mass in anindividual, comprising the steps of: (a) administering a GPR119 agonistto a vertebrate; and (b) determining whether the GPR119 agonistincreases a level of bone mass in the vertebrate; wherein the ability ofthe GPR119 agonist to increase a level of bone mass in the vertebrate isindicative of the GPR119 agonist being a compound useful for treating orpreventing a condition characterized by low bone mass or a compounduseful for increasing bone mass in an individual.
 29. The method ofclaim 28, wherein the vertebrate is a non-human vertebrate.
 30. A methodaccording to any one of claims 25 to 29, wherein the GPR119 agonist isan agonist of human GPR119.
 31. A method according to any one of claims25 to 29, wherein the GPR119 agonist is a selective GPR119 agonist. 32.A method according to any one of claims 25 to 29, wherein the GPR119agonist has an EC₅₀ of less than a value selected from the groupconsisting of 10 μM, 1 μM and 100 nM.
 33. A method according to any oneof claims 25 to 29, wherein the GPR119 agonist is a small molecule. 34.A method for identifying GIP secretagogues, compounds useful forpreventing or treating a condition characterized by low bone mass, orcompounds useful for increasing bone mass in an individual, comprisingthe steps of: (a) contacting a G protein-coupled receptor with anoptionally labeled known ligand to the receptor in the presence orabsence of a test compound, wherein the G protein-coupled receptorcomprises an amino acid sequence selected from the group consisting of:(i) amino acids 1-335 of SEQ ID NO:2; (ii) amino acids 2-335 of SEQ IDNO:2; (iii) amino acids 2-335 of SEQ ID NO:2, with the proviso that thereceptor does not comprise the amino acid sequence of SEQ ID NO:2; (iv)the amino acid sequence of a G protein-coupled receptor encoded by apolynucleotide that is amplifiable by polymerase chain reaction (PCR) ona human DNA sample using specific primers SEQ ID NO:3 and SEQ ID NO:4;(v) the amino acid sequence of a G protein-coupled receptor encoded by apolynucleotide hybridizing under conditions of high stringency to thecomplement of SEQ ID NO:1; (vi) a variant of SEQ ID NO: 2; (vii) theamino acid sequence of (vi) when selected from the group consisting of:(a′) the amino acid sequence of a G protein-coupled receptor having atleast about 80% identity to SEQ ID NO: 2; and (b′) the amino acidsequence of a G protein-coupled receptor comprising at least 20contiguous amino acids of SEQ ID NO: 2; (viii) the amino acid sequenceof a constitutively active version of a G protein-coupled receptorhaving SEQ ID NO: 2; and (ix) a biologically active fragment of any oneof (i) to (viii); and (b) detecting the complex between said knownligand and said receptor; and (c) determining whether less of saidcomplex is formed in the presence of the test compound than in theabsence of the test compound; wherein said determination is indicativeof the test compound being a GIP secretagogue, a compound useful fortreating or preventing a condition characterized by low bone mass, or acompound useful for increasing bone mass in an individual.
 35. A methodfor identifying GIP secretagogues, compounds useful for preventing ortreating a condition characterized by low bone mass, or compounds usefulfor increasing bone mass in an individual, comprising the steps of themethod of claim 34, and further comprising: (d) contacting a compound inthe presence of which less of said complex is formed in step (c) invitro with a vertebrate enteroendocrine cell or a cell capable ofsecreting GIP; and (e) determining whether the compound stimulates GIPsecretion from the vertebrate enteroendocrine cell or the cell capableof secreting GIP; wherein the ability of the test compound to stimulateGIP secretion from the vertebrate enteroendocrine cell or cell capableof secreting GIP is indicative of the test compound being a GIPsecretagogue, a compound useful for treating or preventing a conditioncharacterized by low bone mass, or a compound useful for increasing bonemass in an individual.
 36. A method for identifying GIP secretagogues,compounds useful for preventing or treating a condition characterized bylow bone mass, or compounds useful for increasing bone mass in anindividual, comprising the steps of the method of claim 34, and furthercomprising: (d) administering a compound in the presence of which lessof said complex is formed in step (c) to a vertebrate; and (e)determining whether the compound increases a GIP level in thevertebrate; wherein the ability of the test compound to increase a GIPlevel in the vertebrate is indicative of the test compound being a GIPsecretagogue, a compound useful for treating or preventing a conditioncharacterized by low bone mass, or a compound useful for increasing bonemass in an individual.
 37. A method in accordance with claim 36, whereinthe vertebrate is a non-human vertebrate.
 38. A method for identifyingcompounds useful for preventing or treating a condition characterized bylow bone mass or compounds useful for increasing bone mass in anindividual, comprising the steps of the method of claim 34, and furthercomprising: (d) administering a compound in the presence of which lessof said complex is formed in step (c) to a vertebrate; and (e)determining whether the compound increases a level of bone mass in thevertebrate; wherein the ability of the test compound to increase a levelof bone mass in the vertebrate is indicative of the test compound beinga compound useful for treating or preventing a condition characterizedby low bone mass or a compound useful for increasing bone mass in anindividual.
 39. A method in accordance with claim 38, wherein thevertebrate is a non-human vertebrate.
 40. The method of claim 34,wherein the receptor is recombinant.
 41. The method of claim 34, whereinthe host cell comprises an expression vector, said expression vectorcomprising a polynucleotide encoding the G protein-coupled receptor. 42.The method of claim 34, wherein the known ligand is a GPR119 agonist.43. The method of claim 42, wherein the GPR119 agonist is an agonist ofhuman GPR119.
 44. The method of claim 42, wherein the GPR119 agonist hasan EC₅₀ of less than a value selected from the group consisting of 10μM, 1 μM and 100 nM.
 45. The method of claim 42, wherein the GPR119agonist is a small molecule.
 46. The method of claim 34, wherein thetest compound is a small molecule.
 47. The method of claim 34, whereinthe receptor comprises the amino acid sequence of a G protein-coupledreceptor having at least about 80% identity to SEQ ID NO:
 2. 48. Themethod of claim 34, wherein the receptor comprises the amino acidsequence of SEQ ID NO:
 2. 49.-73. (canceled)
 74. A method foridentifying GIP secretagogues, compounds useful for preventing ortreating a condition characterized by low bone mass, or compounds usefulfor increasing bone mass in an individual, comprising the steps of: (a)contacting a test compound with a host cell or with membrane of a hostcell comprising a G protein-coupled receptor, wherein the Gprotein-coupled receptor comprises an amino acid sequence selected fromthe group consisting of: (i) amino acids 1-335 of SEQ ID NO:2; (ii)amino acids 2-335 of SEQ ID NO:2; (iii) amino acids 2-335 of SEQ IDNO:2, with the proviso that the receptor does not comprise the aminoacid sequence of SEQ ID NO:2; (iv) the amino acid sequence of a Gprotein-coupled receptor encoded by a polynucleotide that is amplifiableby polymerase chain reaction (PCR) on a human DNA sample using specificprimers SEQ ID NO:3 and SEQ ID NO:4; (v) the amino acid sequence of a Gprotein-coupled receptor encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO:1; (vi) avariant of SEQ ID NO: 2; (vii) the amino acid sequence of (vi) whenselected from the group consisting of: (a′) the amino acid sequence of aG protein-coupled receptor having at least about 80% identity to SEQ IDNO: 2; and (b′) the amino acid sequence of a G protein-coupled receptorcomprising at least 20 contiguous amino acids of SEQ ID NO: 2; (viii)the amino acid sequence of a constitutively active version of a Gprotein-coupled receptor having SEQ ID NO: 2; and (ix) a biologicallyactive fragment of any one of (i) to (viii); and (b) determining theability of the test compound to stimulate functionality of the receptor;wherein the ability of the test compound to stimulate functionality ofthe receptor is indicative of the test compound being a GIPsecretagogue, a compound useful for treating or preventing a conditioncharacterized by low bone mass, or a compound useful for increasing bonemass in an individual; (c) contacting a compound which stimulatesfunctionality of the receptor in step (b) in vitro with a vertebrateenteroendocrine cell or a cell capable of secreting GIP; and (d)determining whether the compound stimulates GIP secretion from thevertebrate enteroendocrine cell or the cell capable of secreting GIP;wherein the ability of the test compound to stimulate GIP secretion fromthe vertebrate enteroendocrine cell or cell capable of secreting GIP isfurther indicative of the test compound being a GIP secretagogue, acompound useful for treating or preventing a condition characterized bylow bone mass, or a compound useful for increasing bone mass in anindividual.
 75. A method for identifying GIP secretagogues, compoundsuseful for preventing or treating a condition characterized by low bonemass, or compounds useful for increasing bone mass in an individual,comprising the steps of: (a) contacting a test compound with a host cellor with membrane of a host cell comprising a G protein-coupled receptor,wherein the G protein-coupled receptor comprises an amino acid sequenceselected from the group consisting of: (i) amino acids 1-335 of SEQ IDNO:2; (ii) amino acids 2-335 of SEQ ID NO:2; (iii) amino acids 2-335 ofSEQ ID NO:2, with the proviso that the receptor does not comprise theamino acid sequence of SEQ ID NO:2; (iv) the amino acid sequence of a Gprotein-coupled receptor encoded by a polynucleotide that is amplifiableby polymerase chain reaction (PCR) on a human DNA sample using specificprimers SEQ ID NO:3 and SEQ ID NO:4; (v) the amino acid sequence of a Gprotein-coupled receptor encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO:1; (vi) avariant of SEQ ID NO: 2; (vii) the amino acid sequence of (vi) whenselected from the group consisting of: (a′) the amino acid sequence of aG protein-coupled receptor having at least about 80% identity to SEQ IDNO: 2; and (b′) the amino acid sequence of a G protein-coupled receptorcomprising at least 20 contiguous amino acids of SEQ ID NO: 2; (viii)the amino acid sequence of a constitutively active version of a Gprotein-coupled receptor having SEQ ID NO: 2; and (ix) a biologicallyactive fragment of any one of (i) to (viii); and (b) determining theability of the test compound to stimulate functionality of the receptor;wherein the ability of the test compound to stimulate functionality ofthe receptor is indicative of the test compound being a GIPsecretagogue, a compound useful for treating or preventing a conditioncharacterized by low bone mass, or a compound useful for increasing bonemass in an individual; (c) administering a compound which stimulatesfunctionality of the receptor in step (b) to a vertebrate; and (d)determining whether the compound increases a GIP level in thevertebrate; wherein the ability of the test compound to increase a GIPlevel in the vertebrate is further indicative of the test compound beinga GIP secretagogue, a compound useful for treating or preventing acondition characterized by low bone mass, or a compound useful forincreasing bone mass in an individual.
 76. A method in accordance withclaim 75, wherein the vertebrate is a non-human vertebrate.
 77. A methodfor identifying GIP secretagogues, compounds useful for preventing ortreating a condition characterized by low bone mass, or compounds usefulfor increasing bone mass in an individual, comprising the steps of: (a)contacting a test compound with a host cell or with membrane of a hostcell comprising a G protein-coupled receptor, wherein the Gprotein-coupled receptor comprises an amino acid sequence selected fromthe group consisting of: (i) amino acids 1-335 of SEQ ID NO:2; (ii)amino acids 2-335 of SEQ ID NO:2; (iii) amino acids 2-335 of SEQ IDNO:2, with the proviso that the receptor does not comprise the aminoacid sequence of SEQ ID NO:2; (iv) the amino acid sequence of a Gprotein-coupled receptor encoded by a polynucleotide that is amplifiableby polymerase chain reaction (PCR) on a human DNA sample using specificprimers SEQ ID NO:3 and SEQ ID NO:4; (v) the amino acid sequence of a Gprotein-coupled receptor encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO:1; (vi) avariant of SEQ ID NO: 2; (vii) the amino acid sequence of (vi) whenselected from the group consisting of: (a′) the amino acid sequence of aG protein-coupled receptor having at least about 80% identity to SEQ IDNO: 2; and (b′) the amino acid sequence of a G protein-coupled receptorcomprising at least 20 contiguous amino acids of SEQ ID NO: 2; (viii)the amino acid sequence of a constitutively active version of a Gprotein-coupled receptor having SEQ ID NO: 2; and (ix) a biologicallyactive fragment of any one of (i) to (viii); and (b) determining theability of the test compound to stimulate functionality of the receptor;wherein the ability of the test compound to stimulate functionality ofthe receptor is indicative of the test compound being a GIPsecretagogue, a compound useful for treating or preventing a conditioncharacterized by low bone mass, or a compound useful for increasing bonemass in an individual; (c) administering a compound which stimulatesfunctionality of the receptor in step (b) to a vertebrate; and (d)determining whether the compound increases a level of bone mass in thevertebrate; wherein the ability of the test compound to increase a levelof bone mass in the vertebrate is further indicative of the testcompound being a compound useful for treating or preventing a conditioncharacterized by low bone mass or a compound useful for increasing bonemass in an individual.
 78. The method of claim 77, wherein thevertebrate is a non-human vertebrate.
 79. The method of any one ofclaims 74 to 78, wherein the receptor is recombinant.
 80. The method ofany one of claims 74 to 78, wherein the host cell comprises anexpression vector, said expression vector comprising a polynucleotideencoding the G protein-coupled receptor.
 81. The method of any one ofclaims 74 to 78, wherein said determining is through the measurement ofthe level of a second messenger.
 82. The method of claim 81, wherein thesecond messenger is selected from the group consisting of cyclic AMP(cAMP), cyclic GMP (cGMP), inositol 1,4,5-triphosphate (IP₃),diacylglycerol (DAG), MAP kinase activity, MAPK/ERK kinase kinase-1(MEKK1) activity, and Ca²⁺.
 83. The method of claim 82, wherein a levelof cAMP is increased.
 84. The method of any one of claims 74 to 78,wherein said determining is through the use of a Melanophore assay,through the measurement of GTPγS binding to a membrane comprising saidGPCR, or through a reporter assay.
 85. A method in accordance with anyone of claims 74 to 78, wherein the host cell is a mammalian host cell.86. A method in accordance with any one of claims 74 to 78, wherein thehost cell is a yeast host cell.
 87. A method in accordance with any oneof claims 74 to 78, wherein the host cell is a melanophore host cell.88. The method of any one of claims 74 to 78, wherein the test compoundis a small molecule.
 89. The method of any one of claims 74 to 78,wherein the receptor comprises the amino acid sequence of a Gprotein-coupled receptor having at least about 80% identity to SEQ IDNO:
 2. 90. The method of any one of claims 74 to 78, wherein thereceptor comprises the amino acid sequence of SEQ ID NO:
 2. 91. A methodfor identifying GIP secretagogues, compounds useful for preventing ortreating a condition characterized by low bone mass, or compounds usefulfor increasing bone mass in an individual, comprising the steps of: (a)contacting a G protein-coupled receptor with an optionally labeled knownligand to the receptor in the presence or absence of a test compound,wherein the G protein-coupled receptor comprises an amino acid sequenceselected from the group consisting of: (i) amino acids 1-335 of SEQ IDNO:2; (ii) amino acids 2-335 of SEQ ID NO:2; (iii) amino acids 2-335 ofSEQ ID NO:2, with the proviso that the receptor does not comprise theamino acid sequence of SEQ ID NO:2; (iv) the amino acid sequence of a Gprotein-coupled receptor encoded by a polynucleotide that is amplifiableby polymerase chain reaction (PCR) on a human DNA sample using specificprimers SEQ ID NO:3 and SEQ ID NO:4; (v) the amino acid sequence of a Gprotein-coupled receptor encoded by a polynucleotide hybridizing underconditions of high stringency to the complement of SEQ ID NO:1; (vi) avariant of SEQ ID NO: 2; (vii) the amino acid sequence of (vi) whenselected from the group consisting of: (a′) the amino acid sequence of aG protein-coupled receptor having at least about 80% identity to SEQ IDNO: 2; and (b′) the amino acid sequence of a G protein-coupled receptorcomprising at least 20 contiguous amino acids of SEQ ID NO: 2; (viii)the amino acid sequence of a constitutively active version of a Gprotein-coupled receptor having SEQ ID NO: 2; and (ix) a biologicallyactive fragment of any one of (i) to (viii); and (b) detecting thecomplex between said known ligand and said receptor; and (c) determiningwhether less of said complex is formed in the presence of the testcompound than in the absence of the test compound; wherein saiddetermination is indicative of the test compound being a GIPsecretagogue, a compound useful for treating or preventing a conditioncharacterized by low bone mass, or a compound useful for increasing bonemass in an individual; (d) contacting a compound in the presence ofwhich less of said complex is formed in step (c) in vitro with avertebrate enteroendocrine cell or a cell capable of secreting GIP; and(e) determining whether the compound stimulates GIP secretion from thevertebrate enteroendocrine cell or the cell capable of secreting GIP;wherein the ability of the test compound to stimulate GIP secretion fromthe vertebrate enteroendocrine cell or cell capable of secreting GIP isfurther indicative of the test compound being a GIP secretagogue, acompound useful for treating or preventing a condition characterized bylow bone mass, or a compound useful for increasing bone mass in anindividual.
 92. A method for identifying GIP secretagogues, compoundsuseful for preventing or treating a condition characterized by low bonemass, or compounds useful for increasing bone mass in an individual,comprising the steps of: (a) contacting a G protein-coupled receptorwith an optionally labeled known ligand to the receptor in the presenceor absence of a test compound, wherein the G protein-coupled receptorcomprises an amino acid sequence selected from the group consisting of:(i) amino acids 1-335 of SEQ ID NO:2; (ii) amino acids 2-335 of SEQ IDNO:2; (iii) amino acids 2-335 of SEQ ID NO:2, with the proviso that thereceptor does not comprise the amino acid sequence of SEQ ID NO:2; (iv)the amino acid sequence of a G protein-coupled receptor encoded by apolynucleotide that is amplifiable by polymerase chain reaction (PCR) ona human DNA sample using specific primers SEQ ID NO:3 and SEQ ID NO:4;(v) the amino acid sequence of a G protein-coupled receptor encoded by apolynucleotide hybridizing under conditions of high stringency to thecomplement of SEQ ID NO:1; (vi) a variant of SEQ ID NO: 2; (vii) theamino acid sequence of (vi) when selected from the group consisting of:(a′) the amino acid sequence of a G protein-coupled receptor having atleast about 80% identity to SEQ ID NO: 2; and (b′) the amino acidsequence of a G protein-coupled receptor comprising at least 20contiguous amino acids of SEQ ID NO: 2; (viii) the amino acid sequenceof a constitutively active version of a G protein-coupled receptorhaving SEQ ID NO: 2; and (ix) a biologically active fragment of any oneof (i) to (viii); and (b) detecting the complex between said knownligand and said receptor; and (c) determining whether less of saidcomplex is formed in the presence of the test compound than in theabsence of the test compound; wherein said determination is indicativeof the test compound being a GIP secretagogue, a compound useful fortreating or preventing a condition characterized by low bone mass, or acompound useful for increasing bone mass in an individual; (d)administering a compound in the presence of which less of said complexis formed in step (c) to a vertebrate; and (e) determining whether thecompound increases a GIP level in the vertebrate; wherein the ability ofthe test compound to increase a GIP level in the vertebrate is furtherindicative of the test compound being a GIP secretagogue, a compounduseful for treating or preventing a condition characterized by low bonemass, or a compound useful for increasing bone mass in an individual.93. A method in accordance with claim 92, wherein the vertebrate is anon-human vertebrate.
 94. A method for identifying GIP secretagogues,compounds useful for preventing or treating a condition characterized bylow bone mass, or compounds useful for increasing bone mass in anindividual, comprising the steps of: (a) contacting a G protein-coupledreceptor with an optionally labeled known ligand to the receptor in thepresence or absence of a test compound, wherein the G protein-coupledreceptor comprises an amino acid sequence selected from the groupconsisting of: (i) amino acids 1-335 of SEQ ID NO:2; (ii) amino acids2-335 of SEQ ID NO:2; (iii) amino acids 2-335 of SEQ ID NO:2, with theproviso that the receptor does not comprise the amino acid sequence ofSEQ ID NO:2; (iv) the amino acid sequence of a G protein-coupledreceptor encoded by a polynucleotide that is amplifiable by polymerasechain reaction (PCR) on a human DNA sample using specific primers SEQ IDNO:3 and SEQ ID NO:4; (v) the amino acid sequence of a G protein-coupledreceptor encoded by a polynucleotide hybridizing under conditions ofhigh stringency to the complement of SEQ ID NO:1; (vi) a variant of SEQID NO: 2; (vii) the amino acid sequence of (vi) when selected from thegroup consisting of: (a′) the amino acid sequence of a G protein-coupledreceptor having at least about 80% identity to SEQ ID NO: 2; and (b′)the amino acid sequence of a G protein-coupled receptor comprising atleast 20 contiguous amino acids of SEQ ID NO: 2; (viii) the amino acidsequence of a constitutively active version of a G protein-coupledreceptor having SEQ ID NO: 2; and (ix) a biologically active fragment ofany one of (i) to (viii); and (b) detecting the complex between saidknown ligand and said receptor; and (c) determining whether less of saidcomplex is formed in the presence of the test compound than in theabsence of the test compound; wherein said determination is indicativeof the test compound being a GIP secretagogue, a compound useful fortreating or preventing a condition characterized by low bone mass, or acompound useful for increasing bone mass in an individual; (d)administering a compound in the presence of which less of said complexis formed in step (c) to a vertebrate; and (e) determining whether thecompound increases a level of bone mass in the vertebrate; wherein theability of the test compound to increase a level of bone mass in thevertebrate is further indicative of the test compound being a compounduseful for treating or preventing a condition characterized by low bonemass or a compound useful for increasing bone mass in an individual. 95.A method in accordance with claim 94, wherein the vertebrate is anon-human vertebrate.
 96. The method of any one of claims 91 to 95,wherein the receptor is recombinant.
 97. The method of any one of claims91 to 95, wherein the host cell comprises an expression vector, saidexpression vector comprising a polynucleotide encoding the Gprotein-coupled receptor.
 98. The method of any one of claims 91 to 95,wherein the known ligand is a GPR119 agonist.
 99. The method of claim98, wherein the GPR119 agonist is an agonist of human GPR119.
 100. Themethod of claim 98, wherein the GPR119 agonist has an EC₅₀ of less thana value selected from the group consisting of 10 μM, 1 μM and 100 nM.101. The method of claim 98, wherein the GPR119 agonist is a smallmolecule.
 102. The method of any one of claims 91 to 95, wherein thetest compound is a small molecule.
 103. The method of any one of claims91 to 95, wherein the receptor comprises the amino acid sequence of a Gprotein-coupled receptor having at least about 80% identity to SEQ IDNO:
 2. 104. The method of any one of claims 91 to 95, wherein thereceptor comprises the amino acid sequence of SEQ ID NO: 2.